Hi, I think the best thing would be to check your universal credit query with the Gingerbread helpline
On care, he isn’t “doing you a favour”, he’s caring for HIS child and being a dad.
Once you have the answer on universal credit, you could go onto the CMS calculator page and check how much he should be contributing. Then compare against how much he pays now for childcare to decide how you will be better off.
You both have a child, you both have responsibilities to support your child & there are govt guidelines on how the costs should be split. He needs to stop the emotional blackmail. It isn’t about him, or you.
You definitely aren’t alone on this one, I had similar for the first year after separating 💐