MS anyone?

I've been diagnosed with MS for 3 years now. I'm pretty lucky that I am still active. I put a lot of weight on this year having always been overweight but am successfully managing to lose it now. I am on Tysabri infusions once a month but always find it wipes me about a bit for a couple of days afterwards and I can't work out those days. Wondered if anyone else had some of the same problems and any tips to keep motivated whilst feeling rough.