Speaking from my likewise limited experience, I think getting a skill, or getting good at something, is the only way. Confidence is a meme in so far as your typical "le fake it till you make" retard platitude is ineffective; you probably aren't going to be able to convincingly lie to yourself for extended periods unlike the average normalfag who has support structures and cute little experiences they can use as buffers to their delusions; the average wizneet has none.
If you're sick of feeling inferior and despondent, and it's really getting you down, you're unfortunately going to have to do something to try to remedy that. A common take is that you need to feel good, or comfortable, before you do something, but it's actually the opposite, you'll probably have to do something before your reptile lizard brain fleshcage will let you (maybe) feel good. Waiting around and being mindful probably isn't going to work, but if you notice yourself improving at something that you find worthwhile, you're going to feel good.
The hard part is finding something that actually interests you enough for you to want to get good at it. I was lucky in that after going to some job training course for unemployed people, I got a little job there doing graphic design. I didn't care at all for that stuff until the job forced me to take an interest, and I still think it's a bit dumb, but now it's something I can work on, get better at, see generative improvements, and (sometimes) feel good about. I also do drawing, I just started and I'm garbage, but when these pursuits are going well, I feel competent and good about myself, and there's much less space for self-pity. The caveat to this is, because of the lack of those support structures I talked about earlier, you're probably going to tie your entire self-worth to whatever you decide to do. So when it's going well, great, when it's going bad (which it absolutely will when learning something new) you're going to feel awful. The silver lining is you'll have much more time in your day to work on that skill where the normalfag wouldn't, and like an anime protag, it's you vs the world, which is kind of motivating.
I'm not advocating wageslavery but getting a job is probably the easiest shortcut to this, you're forced to be somewhere and do something, and that'll necessitate getting better at whatever that thing is, and you might even have peers treat you like a person (though they might treat you like shit too)Post too long. Click here to view the full text.