here's my 2 cents

1. Joint tax return requires both signatures. You should notify IRS about the fraud and get some money back.

2. Not sure which state you are in, but in the States, mom gets the custody of the child 99% of the time.

3. Is his income higher than yours?  If so, he should be paying for child support.Are you a stay-home mom or you make money than he does?

4. Do you have any joint accounts together?  Do you how much assets he has?  His 401k?  His life insurance policy, if any? Once you're married in the States, as a wife, you are entitiled to half of whatever your hu*****and has.  All the money goes into one basket.

4. I don't think your lawyer is a decent one.  You should fire him and find a better one. Usually, from what I heard, most men are pulling their hair out when it comes to divorce due to all the accumulated expenses. 

You should definitely find out how much money he has first and find a better lawyer.