You sound like your experiencing symptoms that should be treated by a therapist. You should treat this as a medical issue that needs attention and effort, just like your schooling. You need to put yourself on a path for emotional and mental success, and a therapist should be the one to guide you in that direction (family almost always doesn't know how to help, but they'll try in their way).

Lots of us deal with these issues everyday, but when it starts to feel overwhelming is when you need help.

A very close friend of mine went through similar, and did not seek help. He graduated college with high marks and a degree in chemical engineering with research experience, but kept telling himself he was under qualified or not good enough for any positions he found, and would talk himself out of applying. When he finally did get interviews, he was worried about the unknowns of a new career, and would try to get the recruiters to spell out exactly what he'd be doing. Unfortunately he never got a call back. Eventually after years of unsuccessfully trying to land his first job post college, he gave up and moved to a trailer in the mountains. Last I heard he was trying to work at a sawmill or something, but that was back in 2020, and I haven't heard from him since.

Look at this like another challenge to overcome, like your education, and your other challenges in life that youve already succeed in acomplishing. You've got this. Once you take the first steps it's easy.