Break up

hi there. I'm right now feeling so much pain. I just got served by the courts from my ex wife. Asking for lots of money. I'm scared that I'm going to lose everything including my daughter. She's 15. I love my daughter so much. I feel that I won't be able to do anything with my daughter. I now have to find a lawyer which they will want a retainer. I'm just wondering how much of a retainer will they require. Can someone be able to answer.