What should I do?? - Nervous to let boyfriend w/ bipolar claim taxes on baby

My boyfriend and I have been together for 5 years and our son was born in April. For the past 6 months, my boyfriend has had an extra hard time managing his bipolar - went off medications a few times, broke up with me a couple times just to get back together a few days later, he wouldn’t communicate and would just walk away and cut off all contact when he was mad, etc. But a little while ago, he told me that he was tired of having an immature relationship with me and has been doing what he can to prove that he wants to be better. We are looking to find a couples therapist. Which is great, obviously, and everything has been going good. However, I feel like figuring out our tax situation will cause a little bit of tension.

Here is the situation: In that 6 months, my boyfriend has become financially irresponsible. For example, owes over 20K in tools at work, gets paid on Friday’s and usually runs out of money by Monday, used to only help with baby stuff when asked, and, even, for the month of November, told me his money was going to bills so he couldn’t help with our son but I caught on that he was lying and spending on clothes from a YouTuber he likes. I’m talking, his WHOLE check. (600/week). Since we’ve started working on our relationship, he has gotten better with this. He randomly gives me money and says he wants to help. Recently, a few times, he has asked for our son’s tax info because he wants to claim him and it makes me very nervous to give him access to money. He claims he will just give all the money to me. But I don’t feel like it’s been long enough or that our relationship has been rebuilt enough for me to be able to trust that he will be responsible with our son’s tax return money.

The only problem I’m running into is that if I claim him, I don’t think I’ll get as much back. So I have to decide if the cut in the amount of the return is worth avoiding the risk of my boyfriend burning us again.