There is a guideline as to how much child support a non-custodial parent must pay. However,the guideline is based on the assumption that the non-custodial parent earns minimum income (maybe 125% of the poverty line, I am not quite sure about the number). If the non-custodial parent's income is higher that the minimum salary, then the judge will make a decision as to what should be the proper number for child support.
In your case, I suggest you to consult a family attorney at MA. After knowing all your choices and possible chances, you can make a decision on how to proceed with your divorce case. But alway bear in mind that your child's interest should be considered first.