Suppose you do something you know objectively is a sin. There’s no question about it. You logically recognize that it is a morally indefensible behavior. However, you don’t feel bad about it. You don’t regret it. Given a second chance, you’d probably do the same thing, even knowing that it is wrong to do so. Given these facts can you confess the sin? Does the confession mean anything? What if you want to feel guilty about it? Does that help at all? Has anybody been in a similar situation?
Contrition, as required for forgiveness, isn’t really about ‘feeling’ - feelings are fickle and vary from moment to moment.
It’s about an act of the intellect and the will - understanding that the sin offends God, and making a firm resolution to not offend him again. Being human, you may not end up keeping that resolution, but at least at the time you confess you must firmly intend not to do the sin again, even if you are in the same circumstances.
So the first thing to do is pray to the Holy Spirit for the grace to be contrite - to know your sins, know how much they offend God, and resolve to sin no more.
The second is to think a bit about WHY your sin is in fact a sin - think about what exactly about it offends God. Try to put yourself in His shoes a bit, so to speak - imagine the pain that your sin has caused Him. So much so that if you were the only sinner on earth and you had done only that one sin, Christ would’ve had to come, would’ve had to suffer and die, just for that one sin of yours. THAT is how much your sin hurts God.