Cardio with very painful Fibromyalgia?

I need to lose 25 lbs but I was diagnosed with fibromyalgia (inflammation of the joints) last year.
Medication doesn't help the pain. I can't do any harsh cardio like running. I was a gymnast for 15 years and now I'm paying the price.
I can't put too much pressure on my wrists and my knees are very bad.
Help! Any advice?