My husband has the exact same symptoms. His whole body is sore from his eyes down to his feet. Hydrocodone only temporarily relieves him.
He just got back from seeing a Rheumatologist (sp?) and she did tons of bloodwork on him. She said he has an autoimmune problem similar to lupus and that his body was attacking his "good tissue", etc.
She gave him a particular medicine (I can't remember the name) that many arthritis patients take. It seems to be helping some. She also found that he had a low functioning thyroid and put him on synthroid.
He is supposed to go back soon to do a lot more bloodwork.
Of course, I believe that eating healthy and exercise are very important, but we have found that even with doing that, my husband has STILL been sore. Maybe you have an autoimmune problem, too? Good luck!