Anon, I am so sorry you have found yourself in this situation because it sounds incredibly tough. I don't think anyone here can give you a true answer, but I would like to discuss and reflect on several things you've brought up.
>I grew up in a very Catholic family and I to am Catholic and believe that Sex before marriage is wrong. It's hard to explain how I feel about sex exactly because i really like it but feel very guilty afterwards.
This is incredibly common. Your entire life you have been told that God is watching and judging you constantly. So when you break one of the rules he has laid out, you feel very guilty and full of shame, because you have been told you have done something wrong and that your eternal soul is in danger from it. But during the act, because you are human, you enjoy sex and crave it again later. So first you have to ask yourself, even if I completely gave up feeling bad and saying sorry, would God still love me? And the answer is a definite yes. According to the Bible, God's forgiveness is unlimited. So by the very rules you are feeling bad about, you know that your eternal soul is not damned and that all will be forgiven should you ask for it. Plus, what we view as a marriage is very different from when the Bible was written. If you guys are committed to each other, then God views heart vows as a form of marriage. This allows you to set aside the guilt of what you are doing and consider other parts of your problem.
>he starts getting resentful after I shut down his attempts to get frisky.
This concerns me. He isn't respecting your no, and he isn't respecting your shared religion. Marriages must be built on mutual respect and trust, otherwise they will crumble. When you say no about having sex, he must always listen. I have stopped men a few moments after penetration and told them I am not feeling this, and in every situation, they've stopped and respected that. They may ask why, such as, "Is it something I did?" and I just explain that I'm not in the right headspace. They then drop the issue and we fall asleep in each other's arms. Badgering, pleading, sulking, and the silent treatment are not appropriate. I worry that him refusing your no is part of a deeper problem where he doesn't respect you, but if you would like to work on itPost too long. Click here to view the full text.