morningstar,
I'm sorry you have physical pain. I know that can really wear you down. I was in a car accident once and had physical pain for a long time afterward and really thought that I just couldn't handle it.
One time I felt like something outside myself was driving me to suicide. I fought with it for a day and night. It was really frightening. I think for me it was extreme anxiety causing me to feel that way. I also had repressed memories that hadn't surfaced yet. There can be a number of reasons for the way we feel. Don't forget a chemical imbalance can also contribute.
Please see your doctor as soon as possible. Medication could make all the difference and it usually will take 4 to 6 weeks before it works. So the sooner the better. Please feel free to share on the alanon board concerning your relationship. There are some pretty wonderful people over there.
Hugs,
MG