Sounds normal to me, too.
I am 10 months post op and am just starting to get my hot/cold sensation back in my right hand. Still nothing for the rest of my right side. I also still feel no pain on my right side. My surgeon said during surgery,I suffered a brain stem insult, and that is why my right side has no hot/cold sensation and pain sensation. It is wierd, but i am used to it now.
I see you recently completed your surgery. The fact that you can even walk 20 minutes without taking a break is amazing to me. I couldn't walk at all right after my surgery. I was using a walker then a cane and around Sept/Oct I was finally able to walk on my own. My balance is getting better since i rejoined the Y and use the treadmill. However, I agree with everyone else, you must pace yourself, and don't overdue it. Shorter walks, more often should help.
Good luck in your recovery, and may you have continued sucess!!
Denise