I'm too socially anxious to approach people. What do I do?

I'm 20m in college and I have really bad social anxiety, so bad that I'd rather walk up and down 5 flights of stairs multiple times a day just to avoid standing in a lobby and waiting for an elevator. I'm really lonely and I've been wanting to date forever, but even in the last when I had courage I just got bullied and abandoned, so now I'm too scared and anxious to approach anyone I find interesting.

idk I'm just terrified im gonna be perceived as creepy or just get laughed at again, so I've taken the easy way out and haven't spoken to a stranger in probably a full year. the loneliness is getting worse and I want to make a change but I don't know what to do.

my therapist keeps saying I just need to talk to people and this week she gave me homework saying I need to text or call or talk to 2 of my current friends about how lonely I am. honestly I find that impossible, one because I don't wanna be a burden to anyone by randomly trauma dumping them out of the blue, and 2 because when I've opened up this much in the past it's only been used against me and weaponized. my therapist didn't wanna hear the excuses and now I don't know what to do.

yeah I just don't know