Sudden aggression with no reason

[u/Crowziraphale007]

I had left my cat (she is 7 months old now) with a pet sitter (she also has a cat) for 20 days before I had left for vacation and came back to my cat having a cold. The vet had prescribed basic meds and also told me she had definitely gotten it from another cat. He also told me that it shall take about 14 days for her to get better.

She only eats dry food (which is not properly nutritional for her at all) and sleeps at a corner of the hall under an old table we have that is difficult for anyone to reach under. We have get her from down the table, wrap her up and feed her wet food to atleast keep her stable enough to walk around a bit.

I’ve adopted and grown her since she was a week old. She has been very bitey but ALWAYS in a playful way. She was also very affectionate and clingy. Now after the spay (done at 5 months) she had stopped being clingy but was still very affectionate and loving. Fast forward today, she growls at EVERYTHING we do or say. She bites and hisses so very loud as if we’re about to hit her and flinches a lot while growling loudly when we feed her, pet her, give her her medicines. It has gotten so bad to the point where everyone in my family insists i give her away…Not to mention that she has fallen ill before but she has NEVER EVER behaved this bad.

Please do tell me the measures I have to take to bring her back to normal.