Am I being unreasonable ? Selfish ?

My boyfriend and I have a newly one year old and our relationship turned toxic when he was born because my partner has mental health issues but decided to cease treatment (he felt it wasn’t helping) and went through 2 manic episodes. There were two instances where he’s left us at my parents’ house and cut of all contact with me - one time for 3 days and one time for 8 days, both times he talked to other girls. The time he left for a week, I had to repurchase literally anything my son needed because he wouldn’t even let me get anything for him AND didn’t reach out to see how our son was the entire time, even though he hung out with a girl close by my parents’ house and was buying food for her. And offered to buy drinks and dinner for girls he met online. He also just recently started helping with baby. Besides his recent help, he’s only bought two packs of diapers, two cans of formula, and a $10 outfit from Walmart - my son’s entire life. He also previously lied about where money was going and buying insanely expensive clothes.

He also is in debt over $20K because while he was in the manic episode, he spent a bunch of money on tools and clothes through his job.

The only reason I stayed is because before his treatment stopped, we were really happy and he promised that he would stay on treatment and we are doing couple’s therapy as well. He has improved so I’m giving him a chance. I have not told his family the true extent that he had went through in his episodes but they do know he was in bad condition. But his family does his taxes and now they are insisting that I should let him claim the baby. Or at least split it with him evenly so he can pay off some debt. But I don’t feel like I should have to help him pay off debt when a.) he never helped me b.) he’s done a lot to screw me over with our son and c.) he decided to ditch treatment and put himself in episodes. Just because we are working on things doesn’t mean I’m going to act like it never happened.