I've noticed Catholics - particularly women - have a ritual, a guilt ritual. I won't name names, or cite examples with too much detail, to maintain the anonymity that just about everyone deserves on thetheologyofdad.
One should feel guilty when one sins. Sometimes sins are greatly premeditated, sometimes they are almost spontaneous. But choices about things that are not sins fall into the camp of prudent or imprudent actions, the camp of utility. In the case of these types of actions, it is generally irrelevant whether we like the choice or not. For instance, objectively speaking, I need new clothes. Perhaps I like buying new clothes. Irrelevant. I need them. Guilt has no place in this case. The weird kind of guilt associated with such actions is kind of like an atonement I bring for all the yuckiness I perceive in my life.
But the feeling of guilt does not offer atonement. Only Christ's blood atones for sin. You cannot make a situation less immoral by feeling guilty about it, or a situation that is not sinful to begin with somehow better. This is a particularly Catholic problem since we know that contrition is a necessary part of the Sacrament of Confession. It is necessary to make it fruitful, but from the feelings of guilt not one bit of sin is washed away in isolation from the blood of Christ. The feeling of remorse is at best a fruit of grace, as it is a desire not to do it again.
But, let's remember, here we are not talking about sin at all, but a sort of socially useful spiritual payment plan. It is not intrinsically sinful to eat dessert, to buy new clothes, *ahem*, to buy a new minivan, etc., etc. These things do not violate the Law of God; they can, however, violate one's self-conception. In this case, it is guilt itself that is the sin: it is an act that says I wish to perceive myself as a good person. It is an act that says I am better than this.
Your lifestyle is the lifestyle of a sinner. You expect more from yourself. Your hope and trust, though, should be in God, not in this idol you have made of yourself.
As Master Yoda says, Do or do not, guilt will not atone for the fact that you likes things you feel you shouldn't according to your inflated sense of self... (He didn't say all of that.)
There is a certain sagacity attached to Luther's well-known injunction to 'sin boldly.' Luther knew that this life is a vale of tears and that man is himself incapable of anything good independent of the grace of Christ. What one does, then, is always tainted by imperfection. Expecting anything more from this vessel of clay (me) implies that I consider myself a source of goodness.
Yes, you like shoes, chocolate, vacations. These things are either sinful or not. If you decide that, yes, in fact, you need new shoes, buy them, wear them. Your guilty feeling after the fact do not alter the morality of the initial choice, they will not feed the poor or clothe the naked. Buying shoes that you hate rather than that you like will not do this either, so why not buy the ones you like?