Are you in college, are you still studying, do you have a job? You need to do something with your time that will exhaust you and keep you from revolving the same thoughts over and over.
You sometimes post about terrible thoughts you have, those are just suggestions the devil puts in your brain, they last a split-second. As long as you don't consent to them, they aren't sinful. But you build them up into a big thing because of scruples.
Don't even watch movies like that. As soon as you feel your nervousness or melancholy rising up, go do something else. If you have a lustful thought, you chase it away, right? Do the same for a melancholy thought. Don't even come here and write about it. Just treat those inspirations of the devil for what they are. Repress them, ask Mary to fight them off, ignore them the way you'd ignore an annoying fly buzzing around your head.
The melancholic personality that becomes choleric is probably not unusual. I was probably like that myself, though I can't tell which came first, it's a "the chicken or the egg" question. I think anger is often melancholy turned out against the world. After a while you get so sick of beating up on yourself, you think "I'm going to take it out on everyone else for a while, they're the ones who made me so miserable anyway."