Your best weapon in this will probably be to educate yourself about how God really is, so you can dispel any false ideas about Him you may have. Reading good Catholic books about Him should help you at least some.
I think the image of Him as a perfect father really helps us understand Him though. A father sometimes punishes, is sometimes severe (if the child needs correction) ... but a PERFECT father is one who loves the child tenderly, and wants only what is best for the child. Picture a child being given medicine by it's father. The medicine is bitter, and so the child thinks, "doesn't my father love me?! Why would he make me take this horrible stuff?!" The reality is, even when the "harsh" things come from God, they are like medicine... given out of pure love, and care for the child's true welfare. The child may see only that the medicine is bitter. The father sees, without it, the child may be seriously ill or even die. The father's love is greater in giving the medicine than it would be to withhold it.
But also there are times when the father gives the child sweet gifts, listens to the child, just loves his child. God doesn't just have ONLY bitter medicine for us, but also sweet things. He is a father, not a tyrant.
Even people who have not been abused can become scrupulous (wrongly think that just about everything they do is evil or a grave sin) or can come to see this false idea of God as someone ALWAYS angry, ALWAYS punishing. But the truth is that oftentimes such people torture and torment themselves with such thoughts... essentially adding an unbearable weight to the cross God really meant for them, which itself was NOT too heavy.
In other words, a person may have bad health, for example, and that may be their cross in life. But if that person lets this false image of God take control of them without ever dispelling it, they will torment themselves endlessly with thoughts of hopelessness, fear or worst of all, despair. But the truth is that this latter torment is something we add to our cross. Once we realize that we're being deceived, we must fight to banish those thoughts from us, like any other temptation, and have faith in spite of the darkest feelings that God is truly that sweet and loving father, NOT the picture of a merciless tyrant the devil would present to us and terrorize us with. By reading holy books about how God truly is, or hearing about Him from others, we can form a correct idea of Him, and slowly drive out that hideous, false image from our minds and hearts.
I also suffer from such problems, and when these ideas come to me, however horrible or tormented I feel, I simply remind myself, "God is not like that". Sometimes, even reminding myself that God understands our weaknesses, and wants to help us overcome them, can help to get past the trial of the moment.
So if you feel like God is always angry with you, or like you're "oh so rotten" (the devil would rather we think that than let us get anywhere in our spiritual lives), or like God is always angry with you... remind yourself that Jesus is also our Divine Physician. Yes, He sees quite clearly what has gone awry in our souls. BUT... He also desires to help us get better if anything really IS wrong, by helping us kindly with His graces.
Like a father watching at the bedside of a sick child, He is ever there... even if, in the delirium of our sins we have lost touch with that reality, and no longer can "see Him". He is still there loving us, watching over us, and trying to help us get better. Even if, in the throws of sin, as if in a fever, we kick at Him (by our daily failings or weakness), His love is not extinguished. He knows whether or not we MEANT to offend Him, like a father knows a child out of his or her mind with illness, doesn't mean to be hateful if they lash out unconsciously. Yes, the bitter medicine may come. But also the sweet embraces, the concern over what is happening to us, and the tender affections of the Father and Mother ever trying to help us. Yes, that Father even understands that sometimes a child does hateful and spiteful things, for very foolish reasons... like the child who selfishly defies the parent and runs away from home, and will forgive that child when that child is sorry, realizes their mistake, and comes back to Him.
God guide you as you try to fight against these temptations to think of God in a distorted way. I know that they can be heavy, and even suffocating. But if God sees you fighting to see Him clearly, I'm sure He will be pleased, even if it takes time for you to fully recover. Some people fight such thoughts their whole lives. But what is important is that we understand with our minds what the truth is, and with our wills we tell ourselves, "This is the truth, and THAT (the wrong picture) is a lie, and I refuse to believe in the lie. I know what is true".
There are many things in life we cannot help, like a physical handicap, or some circuмstance in our life. But God will not condemn us for the things we couldn't help, such as the temptations we were afflicted with. He will only judge which picture of Him we believed in with our wills, in spite of the horrible feelings... the false one that makes Him into something awful, or the true one... knowing that He is a God of love and of peace and of mercy, no matter what temptations come, or how awful we feel inside about ourselves or our sins.
This is yet another example of why it is SO important to strengthen our wills. So many times the devil plays with our emotions or our thoughts (with temptations)... but we cannot have, as a foundation of our relationship with God, an ever shifting foundation of sand like our feelings. We need the rock-solid foundation of truth and our will to choose it, to keep our relationship with God proper and firm. Inform yourself about the truth about God and His love and mercy, and when the temptations come, if you cannot dispel them with thinking about the truth, and you feel absolutely helpless against the wrong image of God, then simply turn to Him as a small child would and say to Him, "Lord, I am having these wrong ideas or thoughts, but I refuse them. I know that You are loving and merciful, and I believe in the truth, not in the lie the devil is showing me." If it is all you can do, then simply tell Him that you choose the true picture of Him, and then put your trust in Him that He has heard you, and will be by you, continuing to love you even if you are blinded by that temptation (that is, even if you can't get the thoughts out of your mind, or the feelings out of your heart). Tell Him you reject the lies of the devil. If you reject the temptations, then suffering through them will have good merits for you, and will even strengthen your faith, because of your having to fight all of the time for what is right. You will have chosen the right thing, and fighting for it will only prove your real love for God.
Let us always try to have the best Faith in Him. Picture if God was physically present in a room with you, but then the lights were turned off, and you could not move to find Him. What would happen? Well, you would KNOW He is there, even if you couldn't see Him or reach Him. We must know God and trust Him, even in the most complete spiritual darkness. Our feelings or thoughts won't make His infinite goodness change to something else. We must remember that whatever we are tempted to think, or however we feel, the REALITY does not change. Even if we feel completely lost, the REALITY is that God is merciful, that He does love us (enough to suffer and die for us on the cross!) and can, and WOULD (and died to) save us.
When you learn to recall the reality and place it over your feelings or temptations, the temptations become powerless to do what they were intended by the enemy to accomplish, and can become even a means of grace, as your struggle to do what is right proves to God again and again your faith and love for Him. You may still suffer the thoughts, but if God knows you refuse to believe in those wrong ideas, and that you continue to believe in the right idea of Him, THAT is what is important, even if you keep having the temptations.