It may not be hard to get to a veterinary school, depending where you live. When our dog had bone cancer, I did a Google search for universities with veterinary programs. It turned out to be the best decision, even though it was 3 hours away.
Our dog got 3+ years more of a happy life, when all of our local vets (I got 3 different opinions) said to put him down.
It was reasonably priced, they often have payment programs, and you get excellent, state of the art care.
There is not much difference between dexamethazone and hydrocortisone, since they are both steroids that act as anti-inflammatories, so you did not cause any additional problems by switching the medications.
Are there any veterinary referral hospitals or veterinary schools in your state or within driving distance? Because it really would be best to have a veterinary opthalmologist examine Gidget's eyes and prescribe the best treatment for her. Glaucoma may or may not be painful. But the average vet cannot just prescribe glucoma medications without a definitive diagnosis, and without the right medical equipment it is difficult to diagnose glucoma.
Optimmune is not for glucoma but is for the management of chronic keratoconjunctivitis sicca (KCS), or dry eye.