Repenting

I have a question.. Recently I have been alot more interested in god and the bible and Christianity. My fiancee is christan although he has sinned/sins. He wanted to stop having sex before we are married in April, he said we need to repent so that we can be forgiven and not disobey god and enter heaven oneday. I also had a bad habbit a little while ago of shoplifting. Mostly food, but sometimes I would steal clothes and things too. Which i have stopped now. But my problem now is that although i know we need to stop our sins and repent but I cant feel the regret i need to repent. The bible says that we need to feel sorrow and regret when we repent or else it isn't genuine. But i dont feel like i regret shoplifting. It was wrong and i know that, which is why i stopped. But I was not introduced to God till after I met and had slept with my now fiancee.. My question is, how can i feel regret? sorrow? towards my sins. I WANT to.. I just dont. 😭😭😭