Any chance this was a "burn"- over-exposure to heat source (typically happens over 90* from un-regulated heat sources)?
BPs seem prone to not recognizing when they're too hot, & don't move away until injured- thus it's essential to use thermostats to control all heating devices. IF it's a burn, it's painful, very slow to heal, & can get infected (like yours obviously is) requiring antibiotics from a qualified vet & continuing health care, including topical wound care (Silvadene cream).
Even if it's not a burn, it's potentially serious & even life-threatening- I'm also thinking 'septicemia', so you need a good vet & fast-he'll need to be on the right antibiotic. I hope you can find one that's not too far away. His fasting may well be related, & I'd assume so until proven otherwise. I'm not seeing your snake (this is not the place to diagnose, that's what vets are for) but just throwing out some possibilities that come to my mind.
Reply With Quote