1 year + old female Syrian hamster

[Meowshroom]

I adopted a hamster from a rescue, i named her carrot cake, she had a crusty eye that almost looked like she had scar tissue on her eye lid, months went by and then one day her eye was crusted shut & she lost her eyeball and had no hair around it for a few weeks, she was put on a fruity antibiotic & she slowly grew her fur back but they had determined she had an abscess that “absorbed” or pushed her eye out, i was also given an ointment to put on her eyes, a month or two later aka a few days ago i went to pick her up because I noticed she was out and i was gonna give her some treats, and her belly up to her arm was covered in red lumps that she had chewed on, what seemed like out of no where because she was fine days before, she now has an arm that is very raw from her cleaning/chewing, it almost looks like it has pus on it, and the lumps on her belly now look flat and almost a black color, (infection?)
im very distraught because my sister just spent over $100 for me to take her to the vet not too long ago ): has anyone heard of something like this happening ?She is a rather large hamster and very chunky, she was neutered & microchipped at the rescue (microchip for telling hamsters apart)

[souffle]

It sounds very unusual to neuter and chip a hamster. They are really too small for that and neutering is only done as a last resort if they are ill.
She doesn't sound at all well and she needs to be seen by a vet to see if anything can be done and also if she is suffering in which case she may need to be giver rest.