My cat has a serious overgrooming problem and recently she's been acting a lot worse

So my cat, I think she's around 12, has had an overgrooming problem for as long as I've had her, which I think is about 4 or 5 years now. She has very bad anxiety and even though​​ she doesn't hide anymore, doesnt get scared easily anymore, and doesn't hiss anymore, one behaviour of her anxiety that still persists is her overgrooming.

She will lick herself until her skin bleeds and until she has no fur on her back. I'm pretty sure it's not a skin issue, a long time ago I went to the vet and they gave us meds for her anxiety, to keep her calmer, but they didn't do a lot and my mom didn't think it was worth it (I still live with her, I was a minor at that time just for context). So to help her from hurting herself I started having her wear those surgery rings that are soft like a pillow. I used to also give her onesies but after a while I noticed how uncomfortable she was with them so I stopped having her wear them, now they are only on her if I am washing her pillow.

I usually don't have issues anymore but one night her pillow fell off and I wasn't with her, and now she has two more injuries on her back. A few days later, today, she keeps growling at nothing and looking at her back, I'm really not sure what to do, I have to go to work and I cant take care of her today. She keeps hissing whenever I'm not in the room but when I come back she's calm, I don't have any cat hot spot treatment or anything I can give her. I'm asking for advice, should I schedule a vet appointment asap, is there anything I can get at a store? I live in the usa btw, and thank you in advance​​​​. Also, I'm not sure if sshes spayed or not​​