Child support

I am more than likely going to be induced this next week and I feel more eager than ever to get my ducks in a row. I decided it was a good idea to talk to my now ex bf about what Would feel comfortable for me to get as far as child support. We were originally going to have him cover daycare which would have ended up being a little over $1200 a month... but my sister ended up agreeing to help me with the baby. So I thought it would be fair to ask for $1000 instead. He does not think that is fair and thinks that he should only pay $600 a month. Even though I will be taking primary care of the baby. I really don’t want to have to go to court to figure things out. I’d rather us sort it out together. But he gets super angry when we talk about it. Does anyone have any advice of how to handle the situation?

I should add that I have been planning on him actually being more involved and possibly moving in... until I found out he was inappropriately reaching out to another women behind my back. Not the first time.