Cat sick after prednisone.

Two weeks ago LittleMan had something like an infection in the corners of his mouth sort of like his lips being raw. He was eating great and drinking no personality changes. Took him to the vet no diagnosis given he was given an antibiotic shot and prescribed prednisone 1 ml 2x a day after 7 days down to .5 c2 a day and so on weaning down. Since starting the prednisone the changes have been dramatic and extremely He had started vomiting quite a bit then his appetite started to diminish. He is now extremely lethargic and sits very very still in a half crouched position. He seems dazed and confused and is no longer grooming. He has obviously lost weight as well and sometimes seems unsteady on his feet He does still drink. Called the vet today (thurs) and explained was told prednisone would not do this and they made an appt for next weds. I do not think that if this continues he will last until then. Tues I called in to talk about the vomiting and loss of appetite. They gave me nutri cal. I was and still am giving it to him but a once fastidiously clean cat now won't even lick it off his paws. I will try tomorrow to put directly into his mouth None of this was happening before the prednisone he was nothing like this not even close. I know most cats tolerate this fine. But obviously there is something severely wrong here and I have to do something before I loose him. I will also call tomorrow and tey to get an emergency visit again and pray they will take him. Please any advice right now is desperately needed. We live in a rural town and there are no other vets. I am also emailing pictures of LittleMan 2 weeks ago and his mouth and a pic of LittleMan today

Thank you Dr Marie
I did get him in for an emergency visit yesterday. The vet thought from what he saw he would either have a very high temp or his kidneys were beginning to shut down. Tests proved that neither were the case. He also tested neg for fiv and leukaemia Hid blood work did show that there are high levels if inflammation in his body. But for now we still have no idea what is wrong with him. We are assist feeding him now(and that is not going well i have a fractured shoulder) and vet gave us a different course of antibiotic So hopefully over the next week or so we will see some improvement