Strongly not sign anything before your attorney review it
I am kind of in the same boat, but I don't have a kid.Though you don't have to retain an attorney, I would suggest you get an attorney to review your document and child suppot first.
Somebody told me around $850 you will get a nice attorney to review the documents and present you the risks.
Do more research before you sign the documents. I do understand you may feel difficult to live with your hu*****and. My strategy is trying my best not to see him or talk to him.