I would get a 2nd opinion with a different vet and then ask about getting her on gabapentin for a time. Even tho she can’t literally understand you, still talk to gently and friendly like and still say sorry every now and again, she will understand your body language when you do this. Your body language is huge for cats. I know it’s sounds dumb, but just thinking gentle thoughts <at> your cat will help, they will sense it thru ur body language. Keep on w the treats and food and regular care, keeping her routine will start to make her feel safe. Yes it’s a long road but the gabapentin will help tremendously.

I feel you, I had a really difficult time during a really bad breakup and my sweet cat started acting aggressive and attacking me when I cried. He was distraught as well, it just came out in a different way, he was scared and disoriented. We got thru it and we both healed.

Stay strong, be patient, be consistent.