Yes Vet NOW!
I am pretty familiar with most health issues. It sounds like you have a couple issues going on but the only thing I can tell you is There is an infection going on. Of course I am not a vet and I can honestly tell you that whatever anyone says is only really a guess based off of the things you have told us.
Whatever the case is your snake needs to see a vet immediately. This has obviously gotten past the home treatment part and now you are at antibiotics part and removal of an abcess most likely.

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