Lump under my guinea pigs eye

[meghan_m_25]

Hi.
I have noticed a lump just under my guinea pigs right eye. He was at the vet a few months ago and I pointed it out but she didn't seem at all worried about it. Now I think it was grown a little. He was bred by a breeder and I think he was the runt as all the others in the litter picked on him and now there's a hole in his ear. And he is blind in his left eye. My aunt rescued him from a friend of hers and gave him to me. Does anyone have an idea of what it could be? I hope it isn't something like cancer. My parents have already spent over $100 on him as he had some sort of skin problem on his lower back. and then now we have a puppy and she was there a few weeks ago and was started on her needles and that was close to $100. I get really paranoid about anything that I notice different on him and the puppy. So they are not really interested in spending money on things that I notice. He also has a spot on his back just behind his shoulders and it was dry and thats why we origanlly took him to the vet so she gave us some special aloe and something shampoo. it helped the dry skin on his lower back but this spot is still sore on him you cannot touch it and everywhere behind it he squals and trys to run.
Any ideas??