Omg! You poor thing!
I can't believe they put you in the psych ward. It's bad enough to be accused of having delusional parasitosis but for them to lock you up in truly frightening. I'd run as fast as I could from that doctor or doctors and hope they don't have some way to scar your medical records to follow you to another doctor.
Just my personal opinion, but I'd be very cautious what you tell the doctors. They are often clueless and I've yet to find one that can help me with a diagnosis and I've been struggling to get well for over four years. I've had to educate myself and I'm still working to find medical care. But, I hate having to tell the doctors what's going on and trying to explain it all over and over. I've visited three different dermatologists and two different regular doctors. The dermatologists are always the least helpful and I will never visit one again despite my symptoms include a terrible rash.
Im not as well versed in RX as many people here so I'll leave that advice to others. But, I did find I could obtain medicine from an online pharmacy called my everyday chemist and that has been very helpful.
Avoid sugar. get some sun and try to exercise a little every day. Take your dog to a good vet and make sure they get treated.
Stay strong. You can beat this!