CathInfo.com

God is a perfectly simple being.  He does not vary, as do human beings, from being just one moment and then merciful the next.  Every act of His is at the same time both perfectly just and perfectly merciful.  Flabius ignores the part about mercy, because he has none.  Flabius, you should be very afraid for your soul, since, as Our Lord taught, with whatever measure you judge others, so too will you be judged.  Show mercy, and you will be shown mercy.  Please meditate on the corollary to this.

In any case, as I said, every act of God is both at the same time perfectly just AND perfectly merciful.  He may in fact withhold graces when He knows they will be rejected, and in this way the souls is spared the additional punishment for having rejected the grace.

Catholic predestination, however, works within the bounds of free will.  At no point is the will fixed toward the end, and it is in fact more in line with foreknowledge than it is with any curtailment of free will ... so not the Jansenist view held by Flabius.

Predestination is a Catholic teaching. God is free to predestine some to eternal glory and withhold His grace from others leaving them in their sins without consideration of foreseen merit.

"I answer that, God does reprobate some. For it was said above (Article 1) that predestination is a part of providence. To providence, however, it belongs to permit certain defects in those things which are subject to providence, as was said above (Question 22, Article 2). Thus, as men are ordained to eternal life through the providence of God, it likewise is part of that providence to permit some to fall away from that end; this is called reprobation. Thus, as predestination is a part of providence, in regard to those ordained to eternal salvation, so reprobation is a part of providence in regard to those who turn aside from that end. Hence reprobation implies not only foreknowledge, but also something more, as does providence, as was said above (Question 22, Article 1). Therefore, as predestination includes the will to confer grace and glory; so also reprobation includes the will to permit a person to fall into sin, and to impose the punishment of damnation on account of that sin." ST I, q. 23, a. 3

"God wills to manifest His goodness in men; in respect to those whom He predestines, by means of His mercy, as sparing them; and in respect of others, whom he reprobates, by means of His justice, in punishing them. This is the reason why God elects some and rejects others. To this the Apostle refers, saying (Romans ix., 22-23): "What if God, willing to show His wrath [that is, the vengeance of His justice], and to make His power known, endured [that is, permitted] with much patience vessels of wrath, fitted for destruction; that He might show the riches of His glory on the vessels of mercy, which He hath prepared unto glory" and (2 Timothy ii., 20): "But in a great house there are not only vessels of gold and silver; but also of wood and of earth; and some, indeed, unto honor, but some unto dishonor." Yet why He chooses some for glory, and reprobates others, has no reason, except the divine will. Whence Augustine says (Tract. xxvi. in Joan.): "Why He draws one, and another He draws not, seek not to judge, if thou dost not wish to err." ST I, q. 23, a. 5, ad 3

Predestination in the sense that some souls are predestined for Heaven is Catholic teaching. However, those souls are very few, and the Church DOES NOT teach that any souls are predestined for Hell. So the matter of whether or not your souls is predestined for Heaven is not something you should worry about, you almost certainly aren't - but you still can go to Heaven. 

I was in no way referring to double predestination if you had assumed that.

Look.  What is wrong with you, man?  We have in the OP a soul who's being tempted to despair, and what do you do?  You cite predestination in such a way as to confirm his paranoia.  "Yep, God could be withholding grace from you and abandoning you."  You might as well be giving a nudge to a person standing on a ledge contemplating whether to jump.  Are you deranged?  There's something wrong with you; you need to see a good Catholic psychologist.  There's no such things in reality as God abandoning any soul.  It's the soul that abandons God, as God wills the salvation of all.