This is going to sound harsh, but frankly it really sounds like you're the problem in this case.

Based on some of the things you've said, it's likely that people find your attitude/behavior emotionally draining, and end up distancing themselves from you.

Like this:
Quote Originally Posted by Crustyman View Post
Anyways, during a particularly tough dungeon in the MMO we were playing I had a complete meltdown because I wasn't preforming well enough on this one encounter, and thought they wouldn't wanna do anything with me after that, so I left the discord. After I got some sense back into my body, I tried to apologize but the leader of the third FC said that I simply wasn't meant for the discord due to me leaving and joining the discord as well as the xiv fc multiple times.
That's honestly some super red-flag kinda stuff that indicates instability people may just not have the energy to deal with. It's also not normal to feel such extreme bitterness towards your friends interests, and I can pretty much guarantee they can pick up on that bitterness/disdain when they interact with you, which leads them to interact with you less and less.