Finding suitable work for mentally ill people?

I've always had mental health issues and have been in and out of hospitals because of them, even when I was in school. I've almost always had bad experiences with work; I've never been able to stick with anything for long.

After graduating from high school, I first started studying, then dropped out, and then at some point did an apprenticeship (first year of vocational school, then as "in-company rehabilitation through retraining").

I got a job twice through a measure where the employer paid me a subsidy for three months if I was taken on afterwards. One was 30 hours a week and limited to 14 months, the second was full-time and permanent but I had to do a lot of overtime and it all didn't work out. Then after a year and a half I had a nervous breakdown and was unemployed again. I went to a clinic and then did a year of vocational training with two internships, but couldn't find a job after that. Then I got another internship through a social center and then I was on an EU-funded project for a long time with 30 hours a week, but the funding then stopped and the project ended.

Then I started studying again and got my bachelor's degree, thinking that I could find a better-paying job where I could live off of it if I only worked part-time. I didn't actually complete my required internship, but instead made up the hours with a part-time job over a longer period, which was recognized based on my professional experience.

After that, I applied for a position that would have required a master's degree, but by chance, I was able to work there part-time for a year in my training position as a parental leave replacement. Then I went back to the clinic, and after that, I did my Federal Voluntary Service, which was extended to two years due to the coronavirus pandemic.

Then my mother died, which threw me off track again and led to a longer break. Most recently, I did another six-month vocational training course with a three-month internship in remote work, full-time at first, but then I had to reduce it to 30 hours because I was overwhelmed.

Then my partner broke up with me after 10 years and I gave up applying for jobs pretty quickly after that because I didn't need to earn money quite as urgently now because of the inheritance, but mostly because I'm totally frustrated because I've done a lot of application training and all that, but I just can't manage to sell myself well in interviews, my CV is crap with all the gaps and measures, I'm not making any progress in gaining enough new practical experience, I should have really done a traineeship after studying but that's only available full-time and I know that I'm just not mentally resilient enough for full-time work.

The theoretical aspects were always easiest for me, like school and university. Now I've been unemployed for a good year, and I just don't know what to do. I don't even know what kind of job would suit me, given my shortcomings. I don't want to be over-challenged, but I also don't want to be under-challenged (especially intellectually). Do you have any other ideas?