My ex can't afford to have the kids on her own. She doesn't make enough for all the bills. They need me to provide for them. But I won't be able to provide for

My ex can't afford to have the kids on her own. She doesn't make enough for all the bills. They need me to provide for them. But I won't be able to provide for them and my own rent on a McDonald's income. And I won't be able to keep a McDonald's job if I'm homeless. So the only choice I have is to do everything I can to find a job that pays what I need. Even if it's utterly humiliating.