What Causes Poor Body Balance With History Of Non-hodgkin Lymphoma?

Balance problem: 9yrs back I was a NHL (non-Hodgkin lymphoma) patient in remission (no evidence of disease). I went through chemo treatment 9yrs back. For last one year I have developed tendency to fall i.e. losing balance. One Neurophysician recommended vitamin B12. My present problems: 1. Difficulty in sitting into or getting out of a CAR. 2. Difficulty in getting up or sitting in chair. 3. Difficulty in climbing stars and getting down stairs 2. Balancing problem while moving around. 4. Difficulty in writing and signing. 5. Tendency to lose balance. 6. Tendency to fall down. 7. I am 71yrs.I feel I am of 80 or 90 yrs. age. 8. Movements are like a drunkard while moving around normally. 9. Losing balance like a child learning to walk. 10. Difficulty expressing myself. Difficulty in word-finding 11. Relaxing of body muscles not possible earlier it was possible 12. One way valve of stomach week I feel. 13. Swallowing problems of water, going the wrong way. 14. Not able expand chest like earlier during yogic breathing. 15. Soles of the feet have become very sensitive. Has to wear slippers in the house Is it Myotonic dystrophy type 1 (DM1), also called Steinert disease? What is the problem