University has altered my perception of friendships

Hi, I am a 22F. After graduating college and enduring mental health problems throughout undergrad to the point where it has drove several people away (multiple people have blocked/unfollowed me on social media, I will admit I have said and done things that I regret), along with losing connection with the majority of people that I knew from college (I would say that post-grad, roughly five people from uni text me, occasionally), I am afraid to make new friends or attend in-personal social events. My perception of friendships has been altered to the point where I have racing, repeating thoughts and worries of people betraying me, excluding me, abandoning me, or cutting me off out of nowhere. As a result, I tend to isolate myself from people to avoid being hurt, sometimes ghosting people, emotionally detaching, or delaying responses to texts. I often will assume the worst of people to avoid being seen as "delusional" or "getting my hopes up" or otherwise *** myself over for choosing to see the best in the wrong people. I do not feel like I fit in anywhere, not even in social groups with people who are similar to me. The most I can do is make maybe one friend in a big group and break off. I recently thought I had made a new best friend before things became emotionally abusive and toxic after three months, and I ended up having to cut off a considerable amount of people out of my social circle as well, since we share so many mutual friends and common interests. I even developed hatred of myself and my body because I thought I was too ugly, too fat, too dark, too poor to make friends in university. I'm thinking of taking medications but at this point I don't know if I am going to heal from everything. I try to find community in online chat rooms and shared spaces, but I have trauma from the *** app (a lot of cyberbullying and exclusion on those servers) and I'm afraid to use other platforms like MeetUp or Bumble BFF. I see all these posts about "every girl deserves a supportive girl group" but I feel like they don't exist or that they're not for girls like me. Every social group I join I always feel like the odd one out or that people are talking *** about me in secret. They say that isolating yourself from others is bad for your health, but I feel like I'm probably safer this way (I cut most of my family members off because I know they dislike me) because I have developed a deep mistrust of others. I don't think that I deserve a healthy friend group, friendships, or relationships.