fight for custody

I gave custody 2years ago to my ex-husband. He had been an over the road truckdriver. He was getting remarried and had gotten a local job that would have him home each night. I was having a baby. I thought it was a good idea. It gave him a chance to get to know them. He divorced last year. I haven't been happy with him for some time now. We argue about everything. I have to stay on him about feeding them right. He lets them cross a busy highway without their bikehelmets. Our son had this fungus that was eating the skin off his fingers. I had to take him for treatment. Our oldest son failed 4th grade and I had to be the one to tell him..the list goes on...I had planned to take him back to court after July to get custody back. I am getting married and have spent every penny extra I had (he knows that). But he filed first (I had no clue he was going to do this). Now it's going to look like I just don't want to pay more support. I admit I don't pay that much but it was what I could afford and it was the same amount he had been paying me. What can I do..I can't afford an attorney now. It will take me some time to come up with the money. What do I do now I only have 20 days to respond. I won't be able to afford it until late july or August. Please help!

??????????