Feeling more lonely than usual even when I'm around other people

Hi all! I've never posted here before so I'm still figuring things out but I thought I could use it to talk about how I'm currently feeling

Recently I've been feeling even more lonely than usual & getting too in my own head when I'm around other people. I'll convince myself they don't want me around or that they don't care if they see me or not etc. I don't really have any friends who invite me places or check in with me, I just tag along to things sometimes. I've been avoiding social situations because I don't wanna feel like this, but isolating myself is also making me more lonely

Rcently I went to the pub & for various reasons I ended up alone with this one guy who I'd consider a friend but only because of mutual friends really. The guy chose to leave rather than spend a little time with me whilst waiting for the others. I know people have their own stuff going on & there could be various other reasons for this but I've been feeling down all day today thinking that he left because he was so uncomfortable being around me. Because I'm awkward & shy & my head goes blank so I feel like I can't contribute much to conversation. So I'm worried that I scared him off. I feel like I'm incapable of even basic interactions and that my company is an inconvenience and uncomfortable for everyone I know