Are you physically active? Are you at a healthy BMI?
I've read where a good body weight and regular aerobic activity (such as brisk walking, if that's a safe practice or can be worked up to the point where it becomes a safe practice) can not only help avoid FM, but greatly help with alleviating the symptoms for sufferers.
You're now wheelchair bound so more than short bits of walking may be beyond you. And it can be hard to do aerobic exercise with just your arms propelling yourself in a wheelchair (though, worth trying imo). Perhaps a local swimming pool might provide an outlet for exercising?
Try aloe Vera supplements, with tumeric curcumin supplements and omega 3-6-9 supplements. Works really well for me. Let me know how it goes
Hard to answer without more data. Is the pain from cramps? Stiffness? Some of the others mentioned ideas like warm water therapy in a pool might help. I have to lose weight which I hope will help me. I have trouble walking, due to bursitis the last 3 years. I am a bit hesitant to deal with it but that is my next step I guess.