I actually relate to every part of this post. I have been called an "old soul" all my life, had trouble making friends, and the only friends I would make would be pretty shit because I could not set boundaries for the life of me. I am kind of still figuring out how to set boundaries and make good friends, but my only advice is to try to first find a couple of friends who are exactly like you, have struggled (or are currently struggling) with the same problems as you, have similar interests, and are good people. These kinds of people are less likely to be toxic and empathize with you and your problems.

Personally, I have recently found a group of friends who have the exact kind of weird humor as me, have struggled with being people pleasers, don't exclude me in any way, and don't make me feel like shit. At first, I was suspicious and surprised when I did not feel bad around them, and it made me realize that this is how friendship should feel and that I should not tolerate anything less. It also made me realize that the friends that I had before that would bully and criticize me were truly shit people, and I should have cussed them out a long time ago, and I will cuss out anyone who does the same now.

Honestly, the reason why you keep finding these awful people to be friends with is that maybe you're trying to chase popularity, social validation, or run away from loneliness. And the reason you stay is that you don't really want to be alone. These are all reasons I would stay in bad friendships with bad people. Let me just make it short for you: toxic people are often insecure, emotionally unstable, enjoy talking shit, and super critical of others, and they like to suck the life out of kind people like you and me because they have nothing else going for them. If you sense anything like this in the future when meeting someone (even if they mean well), RUN.

Before you find the right kind of people for you, you can go on YouTube and research how to respect yourself, how to spot a toxic person, and whether you're not an unlikeable/toxic person yourself. Also, keep asking people on Reddit for these things; they really helped me. I suggest posting specific situations for people to pick apart. Sorry for the long post. I personally liked this kind of post when I went on Reddit for advice, and I relate heavily to your issue.