Hey guys, i'm having this weird problem which i'm very unsure of.

It first started off with it just being a very very intense swelling on my back, which was quite visible when i looked in the mirror. I tried to ignore it for the first few days but its been maybe a week past now and now its formed a weird crater like thing with blood underneath...

I went ahead and broke the skin and some blood came out, enough to turn my whole tissue red. I tried my best to examine it which was a bit difficult since it was on my back and i found that it has now formed a weird crater like thing around 2-3mm in diameter and is around 5-7mm deep...

Would anyone know whats going on?