Please help our geourgeous girl porsha.

A few months ago porsha took a turn for the worst, she is the most loving and beautiful 4 year old American bulldog. She has 3 cat friends and everyone who meets her just loves her instantly. One day I noticed a small patch of furr missing, no sign of cuts or lumps, couple weeks later one morning I noticed blood all over her. Took her to vets got treated for a abscess thought all will be fine but as she was healing another one burst. So more antibiotics were prescribed but just didn't seem to heal up. More lumps in different parts of her body kept spreading and bursting so more vets visits to try other ways to treat her but she's just getting worse. Vets can't seem to figure what is going on at the same time becoming very costly to try get her treated which is money I just can't come up with in large amounts and vets don't help unless paid at the time. I really need the help to take her back again to get some tests which are not going to be cheap along with trying her on a more costly antibiotic and no doubt more lotions and trying to navigate changing her whole diet to see if this might make a difference. I would really appreciate any help to try and get our beautiful girl better.