Just a little rant, because my depression changed to bitterness.

The story:
I moved to this new town shortly before Corona started. I worked in a few jobs, but struggled with mental illness after half a year. I was never really good with getting to know people as I'm introvert, and the work stress made me depressive. I was in hospital for a few weeks and got meds which helped really good. I then was given the chance to join a rehabilitation program to get healthy for work again.
During that program I got to know new people, and also a woman who I started to like. We often talked and had good chemistry. After some weeks, we started to date and even kissed once.
When she left the program and began to work again she didn't have time to meet me for half a year, and since then it's hard to meet her. She has always excuses, but when I ask her what she does, she says that she meets friends. I'm really angry, I trusted this person and we did understand each other. I think she stopped meeting me because of my mental illness. People just don't want me in life.
Similar story happened in the same time. I want to meet new people, but I'm just shy and introvert. I don't know where to start. People stop seeing me after some time. Am I such a bad person? Sometimes I just wish they would say I'm a bad and boring person. The last two years, I gained a handful of friends, but lost all of them. It's sad.