I too am a nominal introvert surrounded by computers, they help keep me occupied in the absence of social interaction (or provide it, via online communities), but this pandemic, especially in the past few months (probably not helped by a miserable winter), has demonstrated to me that I have (and had, even before lockdowns) a severe social interaction deficiency.
Kinda like a vitamin deficiency, I suppose, in that if I don't get enough of it then it has real impacts on my ability to function properly. Since my teenage years, when everybody was free to casually socialise without commitments to other stuff, I've had fewer and fewer opportunities to socialise, and I think it's showing. I'm pretty much down to once or twice a year with old friends because they've moved away, constructed lives, are busy with work and building families. There's one newer friend who I see more frequently, but since we're now doing different things that's become infrequent now too.
I guess what I'm trying to say is that I know the feeling. I'm sure I'm probably a more social person than I allow myself to believe, but because I must pretend to not be that social to disguise the massive hole in my life where socialising should be, I have to pretend it's a smaller hole than it is and that computers are enough to be a substitute.
I don't know how to fix it, clearly, because I'm having issues with it now. But regarding "fitting in", long ago I took on the approach of just... being me. I know, I know, stock template advice, but what I mean is that I don't try to be somebody else. I quickly learned that I can't, it's too exhausting anyway, I'm sure everybody here knows what that's like. Sure, maybe I seem "quirky", and sure, maybe it means there are probably some people who might not want to be friends with somebody who acts the way I do, but that's fine, I wouldn't want to be friends with somebody who expects me to be somebody else anyway.
Now here comes the tricky part: finding new friends. I was never amazing at it in the first place, but as you get older and everybody's silo'ing themselves in their new lives with their partners, kids, busy work life, there's a lot less opportunity for "just hanging out". All of the people I'd consider long-term friends/people I'm still in at least semi-frequent communication with are people I met through education over the years. This includes the friend I mentioned in the second paragraph, a few years ago as a "mature student", they're the most local friend I have right now and without them I'd be miles and miles away from anybody I know.
So I guess what I'm saying - and I know this unfortunately won't work for everybody - is that school and work are some of the biggest, most obvious environments where people will naturally gain familiarity with each other and maybe take that outside of those places. If you're lucky enough to have a job, that seems the obvious logical place to look, I can't say I have any experience there, but it has similar qualities to education in that you probably see people around and probably know them by name, you share the same environment so you have at least one thing in common. Maybe there are a few you could see if they're interested in doing something fun, outside of work? In terms of education, if you (whoever might be reading this post) had bad experiences in elementary/primary school or high/secondary school (I sure did, it sucked, hard), I'd note that college/university can be a much better place to just be yourself than normal kid/teenage school. Maybe even night classes or something, potentially more affordable and more casual, though I've never been to those so I can't really say for sure.
Whew. That's a lot more words than I intended to write when I started this post, but I suppose I covered what I meant to cover, so maybe it's the right amount of words...