Your very first step should be therapy/medication. We're all just randos on the internet and won't be able to give the same personalized treatment as someone who spent the better part of a decade studying this stuff.

Healthy habits will also help. Just 2 hours of walking total in a week makes a huge difference. You can carve out 20 minutes a day and take one day off a week, or do it all in one go on a nature hike. Cut out alcohol entirely if possible, it's literally poison and exacerbates mental health issues. Sleep at least 6 hours, cut down on processed junk.

Beyond that I recommend finding local social spaces, like a board game shop, and going there when you feel ready. You could reach out to the owners and see if any special accommodations can be made. The hardest part will be walking in the door - the trick I use is to tell myself I'll just stick around for 1 hour (30 minutes, 5 minutes, whatever you are able) and then leave if I'm having a bad time.

Aside from that, focus on making friends first and often a relationship will organically grow from there. I won't pretend that it's easy, but it's absolutely possible. You are deserving of love and acceptance just as much as anybody else.

Oops I mean your friend lol.