Hi elgrande.
I was in a similar situation but for different reasons. For me I was getting so sick from the meds that working became a massive struggle. In the end, after battling through for 12 months at work and taking all my sick leave, holiday leave etc in dribs and drabs over the 12 months just to get through, I finally said enough and when my contract ended I decided to take a few months off to simply get well. My GP signed off on temporary sick leave which entitled me to social security for 3 months. Not much and realistically doesnt even cover the mortgage, but it gave me breathing space to concentrate on my health.
One thing I did notice over the 12 months when I tried to work through it though, was that I just got sicker and sicker as my body became run down. I do think that it was something I had to do.
I think going to your GP to discuss it is a really good idea. As you are feeling mentally low, he or she may be able to help you with that which may alleviate some of your problems.
It is not an easy decision to make whatever happens, and I wish you well.
Kat