hi julie and welcome! the first little while with this is especially full of question marks. it's a scary time. you're in good company here though.
re activity, well for sure i personally was not able to do much at first.. i managed to get back to teaching skiing 2 wks after dx but i could not have done it without the chairlift rides to rest in between runs, and i could only teach level 3/4 because i could not hold my own ski poles!
after a year and a bit i decided to get in the pool and start working on my time to swim a kilometer. at first the loss of functionality as my core temp went up would deter me.
then i decided to just swim through it when my hands went floppy and it was fine. it was rough getting balance when i climbed out at the end. i think if i had kept it up the effects might have decreased over time. i haven't had money for the pool in a while, but i found it was good.
anyway, welcome again - lots to read up on here - what i appreciate most about my diagnosis is the crazy learning curve the last 4 yrs have been. happy reading!
READ ME key info on nutrient targets - www.thisisms.com/ftopict-2489.html
my approach: no meds so far - just nutrient-dense anti-inflammatory whole foods, and supplements where needed
info: www.whfoods.com, www.nutritiondata.com