Hi Prauly -
Yoga has many benefits. It benefits the mind (read spirit), as well as the body.
My local chapter of the MS society offers what it calls "recreation" classes of yoga & tai chi. Only $10 for weekly classes for a couple of months. Not $10 per class. $10 for the whole thing! The teachers are knowledgeable about our limitations.
I also have horrid balance issues. Much is done lying on your yoga mat (called a "sticky mat" - to prevent slipping). If it was a standing posture, my teacher would put a chair next to you, so you could hold on. Your instructor will HELP YOU when necessary. If you cannot do something, sit it out. This is not like school, where you are obliged to perform. It is up to YOU.