Moved my entire life for this shitbag human

I moved my entire life six states away. Waited 8 months to bring my son up, visiting back and forth twice a month until we knew it was right. He promised me the world. Then took it all away. We have been back in our home state with no stability, no real family, no job, for two weeks now. Two months ago he wrote me a letter saying he wants a thousand more years with me. Then he has a mental breakdown. Treated my young son like he didn’t even exist. I took care of his sick mom for pennies. He never backed anything up with actions. I’m almost 40. I’m starting all over again. Again. I’m sick to my stomach over it. Walked on eggshells for a year with him. Lost 50 pounds. He lives off of his mommy’s money and smokes weed all day and doesn’t have a job. Red flags everywhere that I ignored because I believed every lying word out of his mouth. He says he’s shut down and has no bandwidth. He completely disrupted and destroyed me and my son’s lives. Starting over sucks. I am so mentally drained and sad.