How to avoid pushing

I am struggling to find the right thing to do. My husband of 15 years decided to leave. Said he wants a separation and told our 10 year old daughter he wants a divorce. He moved out October and he has yet to file anything he came to an agreement to pay an amount for child support but just said last week that we have to revise it because he could barely pay his bills and rent of his new place. (He makes triple of what I make in a month) I have more responsibilities with our daughter. He is to have her every other weekend but she is wanting to spend less time with him and wants to be home with me. I’m struggling myself to make ends meet. My family has been helping me out since he moved out. I have hopes in reconciliation but I feel if he continues to push to pay less in child support I will have no option to reach out to a lawyer/mediation on how to proceed. If I do this I don’t know how to calmly communicate this to him and I really don’t want to push him further away. He is well aware of my financial responsibilities as I shared with him everything he left me with. I also just don’t understand how a husband can walk out and do this to his family.