Child support payment is going to force me to loose my how, what can I do?

I have an 8 month old child. I've been paying her 400 a month now for 6+ months (when she first asked). She has now learned that the state could force me to pay more than 1300 a month and is now taking me to court for it. If I'm ordered to pay this, I'll loose my house. I can't afford this much. I counter-offered with 600 a month but she's insistent that she get the full amount. The court says "I have options and that I can sell my house." Like most, I'm upside-down and there is no way I can sell the house for 75K less than what I owe. I'm stuck. If I loose my house.... how am I to have a stable environment for my baby when I get her... which is 50% of the time!