Hey Sailer -
First off, if your depression is being appropriately managed, you may want to talk to your doctor about adjusting your medication. You'll find it so much easier to stay on a positive track if your symptoms are under control.
Second, I know (really...really...and truly know) how hard it is to motivate yourself to an exercise plan when you're dealing with depression symptoms. BUT...it really does help to alleviate those symptoms. So I'd suggest you start slow. Take a walk. Do a yoga tape. Start getting yourself into a habit of daily movement. It will get easier, but you have to make the commitment first.
We have a great forum here for those 50+, and another forum for those who struggle with depression...these in addition to all of our great groups by eating plan. So look around, find a spot, and settle in.
I can't wait to get to know you better!