I have been on a diet for about 1 week now and I have not drank caffeine since I have been dieting. I have had serious upper neck pain and its giving me a headache. Could not drinking soda cause this?

Hi. I have a condition known as brachial plexus, erbs palsy i am 27 years old and at birth weighed 10 pounds and during the delivery the doctor used forceps on me anddamaged nerves, Now I have trouble doing alot of things i cant eat with it, do any type of over the head movements, it is so weak that i cannot lift something as small as a can of soda, and all the things that i have tried seem to fail b/c of this and wonder if i could still after all this time try to get compensated for it, hate to be so long winded and bad writing but in a hurry any help would be great very depressing situation i am in.