To exercise or not to exercise? Not sure if i should even bother again.

I used to go to the gym in high school. Off and on my while life I would get in gear again and work out at home. These last few months my body has just went downhill bad. Have no energy, sleep a lot, I'm diabetic, have had a pain in my leg that won't go away, same leg and hip have arthritis, I have a bad back, bad knees. I'm afraid to do the exercises I used to to