Stuck in retail

I'm currently stuck in a dead end retail job and as someone with severe social anxiety it is extremely stressful. Every interaction with a customer has me coming away from it thinking that the other person hates me, or is annoyed by me, because of some social mishap I made or the fact that I'm just a generally awkward person. And with Christmas coming up the number of customers is becoming too much for me to handle. The store has been flooded with customers lately, and it's hard to actually focus on doing my job when I'm surrounded by all these people, any of whom could potentially stop me and ask me for something, which can quickly stress me out.

My doctor prescribed me buspirone for the anxiety but it hasn't helped much. Or I haven't noticed any effects, at the very least.

These anxiety issues cause me to be extremely drained at the end of the day, thinking over all the awkward stuff I said or did that probably annoyed someone or pissed someone off, whether customer or coworker. And combined with my depression, it means that my ability to look for a new job is very limited. I do the bare minimum looking for jobs and I find nothing, and I don't improve myself or work on my skills either, because I genuinely can't be bothered. Depression or laziness? Maybe both?

Anyway, not sure why I'm posting this. Maybe just to get it out there, to vent. Maybe if someone has advice that'd be nice but I'm not hopeful. I've gotten little great advice in the past, whether through counselling or online support. I just feel hopeless about my ability to change my situation. I need a new job, certainly, but I can't manage to get one. And in the meantime, I'm just getting by day by day, overly anxious in a job that seems tailor-made to target my childhood fears of having to talk to people, a fear that has persisted into adulthood and has made me dread going into work every single day.

TL;DR: Working in retail as someone with severe social anxiety is draining me, leaving me (combined with my depression) unable to find a new job. I feel hopeless, like I can't do anything at all to change my situation.