Your depressed and treating it needs to be a priority. Your refusing to do a PET scan because of anxiety and/or depression. (If it's the anxiety speaking than your afraid of bad news; if it's the depression speaking then you have an unconscious or conscious death wish). You get upset because you're hurting inside but don't know how to express it. Obviously, all this is just my opinion.
There's no doubt that you have a kind spirit! You've got to make healing yourself a priority. You say that you have been given medication. Are you not taking it because you researched the side effects/risks and found it unacceptable? This is the only valid reason for not taking it. I find that I do better on medication but I understand the point of view of people who forgo medication. However, if you can afford it, please start looking for a good therapist. I think the one that I see periodically was able to lift me out of my despair. There are no guarantees other than if you don't take some time everyday to take care of yourself--it's not going to get better! I care about you. Please explore the therapist option and consider medication. Sincerely, Myst