I really relate with what your saying. Since covid hit I have been much the same. I turned down hanging out with friends so much that they don't ask anymore.
The social anxiety is horrible too. I really empathise with you there and you're certainly not alone in that feeling.
This might sound like a silly suggestion - but I have actually found being involved in a hobby outside of the house really helpful. I love sport. So I get involved with a sport that I like and the structured environment makes it easier.
I hope I can explain this clearly. What I mean by the structured environment is that the social pressure feels less daunting, since everyone is there with the same purpose. Another thing is that since you are all there for the sport/hobby, there is something to talk about immediately. Which helps me alot because I struggle with anxiety of not knowing what to say. Also, since it is a group environment, there is less pressure on you to think of stuff to say or even talk at all. You can just float in the background and work up the courage to get involved actively in the conversations down the track.
I play my sport once a week. For me sport helps lift my mood even when I'm really really depressed because it is something I have always loved.
If you dont like sports, there are other options of hobbies. For example there are choirs, clubs for playing certain instruments, groups that play games like dungeons and dragons or other card games, clubs for hobbies like photography, political communities (for any political leanings), dance groups/classes like Zumba, taking classes in things that interest you - instruments, painting, sewing, crocheting/knitting. If you need help looking for something to do, feel free to reply to this and I can look for more specific suggestions for the things you like.
Don't get me wrong, it is sooooo hard to take the first step and go to your first session. But generally once you go, it is not as bad as your brain was telling you it was. And every time it gets easier and easier.
I still struggle with other types of socialising, but my psychologist thinks that this is a really great first step.
You can make it through this <3