I fell out of love but now he is kind of trying

Ive posted before about my husband and i being a great team, working together, parenting our oldest and his bonus daughter who is 9 and even going through extremely challenging situations. I left a cult, i lost my parents and siblings to estrangement and we had 3 early pregnancy losses. Weve been best friends until we had our baby last March. He basically took on the point of view of "you wanted the baby, so take care of the baby" for 10 months, he rarely held the baby, did not participate in really any parenting needs. He did not help with bath time, feeding, diapering, etc. And i was working 2 weeks after birth because even though i begged for a budget, he spent freely. So I wrote a letter to him when baby was 10 months and there wasn't really change. So, I started working more and am going to finish my degree (I have one class left) and leave him but

The last week, he woke up with the baby for about 10 minutes and changed her, he has been dancing and playing with the baby and he has stuck to a budget, sorta

I feel like an asshole because although he is trying ...the damage has been done. Like, I felt abandoned and crazy and lonely and sooooo soooo tired ... and now it's getting better and all I see is an exit strategy. Help!