1. Try to re-engage with the cosplay community or engage with another hobby community

I don't want to be internet psychologist but it seems to me that you have social anxiety. Seeing a therapist would probably be for the best but based on your post history that may not be reasonable. Finding a non-political hangout group might also help you. It's ok (good even) to care about politics but there is a time and a place for it and sometimes you should bite your tongue in order to maintain your social groups.

2. Join an org

I see you talked to PSL, based on this post I'm guessing that did not go well. You could try again or find a local group. Imma be a lib real quick and say there is no issue with joining cpusa or the dsa if you want to find tolerable people to talk with. This ties back into point 1. Socialization is a need, like with food sometimes it requires you to put up with things that aren't perfect.

3. Go to college

I see you have a post asking if it is worth it, here is my take: if your family can financially support you then the new environment is worth it. You will be able to meet an entirely new group of people who are most likely way more liberal (some socialist even) than your hometown.

I would not recommend going into debt just for college, unless your area has a work program to forgive debts (like teaching in underserved counties), or unless your passion is medicine or law where your salary will be enough to cover it. To that end I would recommend starting at a community college or going to a technical school and learning a trade.

I know a couple people in real life, if you don't you can maybe try to convert people who are "apolitical" or don't like the status quo but don't have any solution.