The man jumps jobs

My fiancé has a BAD history with jobs and continuously loses them at least a month after getting one. Since March he’s had 5 jobs. He’s always been a job jumper and there was about a year in our relationship where he didn’t even work WHILE I WAS PREGNANT. I was already struggling pretty hard financially making only about 12$ and paying all of our expensives. I would look for jobs for him and he just would blow it off. Since our son was born in March he’s been getting jobs but he WONT KEEP THEM there’s always an excuse about them. He always promises to find a better one ect and never does. I feel like at this point he’s let me down one too many times and will never actually be able to support our son and help me support him. Anyone else gone through this? What did you do? Opinions?