Help my family stay together

11 years ago I left an abusive marriage, and took my 2 children aged 4 &6. After 6 months living in a domestic violence shelter I was able to save money and get an apartment. I filed for divorce and was granted sole legal and physical custody. I felt like we were finally free. Although I have always been worried he would show up somewhere we lived. I had been a single mom for 5 years when I got remarried and had two more children. Three months ago I got a paper served that my ex husband was trying to get sole custody of our two children. This has been something I prayed would never happen since he has shown little to no interest the past 10 years, not paid consistent child support or tried to improve himself. He never held down. I had to hire a lawyer and respond to his motions. We had to hire a guardian to find out the best interest of the children. All this is taking a severe toll on our family, the recent birth of our youngest. The medical bills. And now all the legal bills. Any amount would be a blessing! I can only imagine we will win in court but getting to trial and all the costs associated are immense. Thank you!