It could be flea allergy dermatitis, or other ectoparasite (skin parasite) with a secondary bacterial pyoderma. Or, it could be a bot or maggot infestation, which is an infestation of fly larvae. To determine if there is an infestation please gently squeeze the skin around the hole to see if larvae or maggots comes out of the holes.
There are many, many possibilities and unfortunately a vet is really necessary to sort this out, since a vet could do diagnostics, such as biopsies. I must put this in even though I know this is not possible, since you are unable to take the cat to the vet.
If the cat will allow you, it might be a great help if you could at least try scrubbing the affected area with Betadyne, and than apply triple antibiotic ointment once per day.
Also try to apply Revolution, Frontline, or other anti-flea and tick topical. I know that you are unable to much more than this. Hope this helps!
I called and asked my mom if I could have her again. My mom is going to talk to my step dad to see if he will let me have her. Keep your fingers crossed