Child Support and dead beat parents

By now just about every one should know I'm a single mother. My daughter will be three in December. My daughters father and I had every intention of getting married. We just had to keep putting it off as our bills and Hannah were our first priority. Through out our relationship my ex's true idenity came out. Definatly wasn't someone I wanted to spend my life with or raise my daughter with. I won't go into detail about all that drama.
Because my ex and I weren't married we had to go to child support agency to determine paternity of Hannah and if he should be paying child suport. Well Hannahs dad and I were on good terms, living together and still talking of getting married. So when the child suport agency rep. asked if we wanted shared placement if we split up. Not thinking we would split up we both agreed.
Had I known that moment in time was going to mess with my life now, I would've never agreed to it. Because we have shared placement, child suport says that her father would only have to pay $55 a month. But they aren't going to make him pay at this time.
Even if he were helping take care of her both physcially and monetarily it would still come out to more than $55 a month. What with child care which is $110 all in its self a week, pull ups, food, toilet paper, soap, shampoo, clothes and shoes, rent and utilities, there is no way $55 dollars would cover even a small fraction of it.
In order to get child support changed, I, having limited resouces as it is now has to pay to get the paper work and pay a filing fee. And if i really wanted to make sure it was done right I would have to pay for a lawyer.
I learned they changed child support laws, that in my opinion protects dead beat parents and makes it harder for the parent taking care of the child to take care of the child and make ends meet.