I went through this when DD's father and I split up.
He was reckless with money, we had a lot of debt (all of which he benefitted from - keeping the big TV/sofas etc). As his credit rating was poor, they were all in joint names.
He had a "breakdown" too busy spending money on OW and didn't pay a penny towards anything. At one point I was paying rent, mortgage, loans and credit cards single handedly as I didn't want my own credit rating to be trashed.
I was extremely lucky in that my parents were supportive and able to help out financially from time to time. When I was finally able to sell our flat after 2 years, I had to pay back my parents £8000. I had borrowed it just to spend on bills. If they hadn't have done that, I would have had to use credit cards to pay my mortgage.
I cleared all of that debt on my own within four years and I supported my DD at the same time. He has to this day never paid any maintenance for her. It was HARD. I was often left with absolutely nothing. I'm so grateful to my parents that they didn't allow me to starve.
I appreciate that I did have support, however I am so bloody proud of myself. I don't owe anything now. I work full time and my career has progressed, I stuck through it and I'm SO proud that I can now provide for my daughter all on my own. I feel like a strong, positive female role model for her.
I don't spend as much time with DD as I would like, but financially I don't have a choice. I'm the one and only breadwinner. I hope that when she is older she will understand how hard I have worked to give her the best that I can. We finally have a nice life.
It will get better. 