Going back for more child support..

So to make this story short. I have a 4 year old since day one I've raised him alone. The baby daddy was abusive and a partier so it was a hard break. As of now he sees our son every Wednesday night and every other weekend, two weekends a month Friday night to Sunday day. I get him back Sunday afternoon. I'm going back for more child support he already pays $333.00/month. But my sons daycare is going up to $840.00/month just for the summer before he goes to kindergarden in August. So I already pay $650.00/month for his daycare now and I'm drowning and beyond poor. I tried asking him for help but he acted like an asshole and said I should get on a government program and he said I said I was going to pay for his schooling on our parenting plan (at the time I was on the program but was terminated, my case worker got fired and closed all her cases. So I've been on a wait list for almost a year now) So I got the papers to go back for more school support and now I just feel so overwhelmed... Words of wisdom or advice please ladies.