Golden Retriever with weird skin infection :(:( Help

Hello!
I have an 8 year old Golden Retriever and her name is Gaia. She has been with me since she was a puppy, but 3 years ago I moved to Chicago and left her with my parents in Mexico until I got settled down. Finally I brought her with me last year on November and after just a few months in she started having very itchy skin, at first we thought it might be the change of weather so we started giving her more fish oil, and adding coconut oil to her meals to see if she would improve but nothing worked. Her skin started to open up in her forearms, her ears, and her stomach and her skin became very flaky. They told us she might be allergic to the weather so she started taking Apoquel and Simplicef and they gave her shots of Cytopoint. Since then we have taken her to the vet almost every week or every two weeks and they just kept giving her more of the same that was not working and her skin just kept getting worse. Now she has no hair left on the right side of her body, her tail, her ears and her legs. She can't even walk without scratching, and shaking. We have tried like seven different medicated shampoos recommended by our vets, giving her a bath every two -three days, she has been on antibiotics and steroids and nothing works. Now for the past week she has been trembling and she just lays in bed all day (she used to be a very active and happy dog). To make things worse, she started getting seizures about a month ago and faints almost every time we got to the park. The vets are now saying her problem is anxiety and they want to give her antidepressants or anxiety medicine because they say that's her problem. Even though she is an anxious dog, I do not believe anxiety could have caused all of this, I'm sure she has something else in her skin that's causing all of this. If you know how we might help Gaia out please let us know, we're desperate and can't keep on paying all this veterinarian bills that have only made everything worse.