Anxious about leaving and about having to deal with custody

I decided to leave my husband, he doesn't know yet. Last time I mentioned a separation, I got called a coward, only for him to come back later and beg me to stay. I am also depressed and angry because I feel like I'm the only one putting in effort into taking care of the house and our son. My husband is a different parent in public tho. Curse these closed off spaces.

I don't trust my husband to be able to take care of our son if we have 50/50 custody, but I don't know what to do...