Jamie,
When we reach this point, outside help is necessary. By all means at least let the doctor come to your home, they are already aware of the situation via your wife, you wont be judged, and will be there to help. You need to be given a diagnosis with proper medication, this isnt something you try to do over the internet yourself. Books are great in CONJUCTION with seeing a doctor, therapist, but to try to medicate and be your own therapist alone is virtually impossible, if not dangerous in some aspects, you need a blood work up done to rule out thyroid problems, and your diabetes definitely needs to be checked again, its long over due. At least allow that doctor into your home, and make your start there. Keeping post, we are here for you. Also keep a diary of your daily thoughts, feelings, symptoms, what you eat, and show it to your doctor, it helps in these situations, as when we see them, its like we have 50 billion things on our minds, and forget half of what we needed to convey or inquire about. This way, they can see if as you felt it that day and can address the situation.
Trish