Do abusive people actually care or feel bad?

I was in an abusive relationship for about a year and a half. Most of the time he was on drugs (he went to rehab for a bit and was probably sober for 2-3 months all together of the year and a half.) He of course gaslit, lied, and manipulated me about his use but he was also just generally emotionally abusive. Im pretty sure he had BPD and I also have BPD so we kinda fed off each other and things escalated very quickly. He couldn't handle my big emotions and I couldn't handle his drug use and we both just amplified each other's problems. When he'd be caught or after a fight he'd apologize, cry, whatever, and I always believed that he really did feel bad but I always wonder because he was a really good liar sometimes.

Obviously whether or not he feels bad doesn't make his abuse towards me an excuse. We weren't good together, even when he was sober because of our both mental health issues I dont ever want to be with him again. But I do wonder if he was actually sorry. Because you can do bad things and really regret them I feel especially if you're not sober making said decisions.