Sinemet no effect, is it PD

Diagnosed at 65 with PD over five years ago (otherwise not overweight fair fitness level). Severe tremor right side  arm and leg no other symptoms for first four years. Then slowly started losing movement same side. Now am not able to lift myself from tub, must get onto hands and knees. Nor am I able to move in bed, must get out of bed and walk to other side as a roll-over. Have been on Clonazepam for past three years in order to control the tremor at night and also Gabapentin (neurontin) two years for neuropathy in feet which I believe was brought on by high dose of sinemet (800 to1100 mg/day for three months). Sinemet does not improve my movement nor the tremor, it's just lke taking candy, and no side effects either. I have always had lower back problems from time to time due to hard labor but nothing serious. Over the past six months my lower back muscles have deteriorated to chronic pain. Unable to wash a load of dishes without taking one or two breaks. I have tried Sinemet at least ten times for periods of one week to three months during the last five years without any benefit. I have read numerous statements on the net stating that 'if there is no benefit from Sinemet it's not Parkinson's'. A British doctor submitted a letter to a neuro journal stating that doctors should me diagnosing patients with Sinemet. I have always been a shy nervous type, went through a rough three and half year divorce and prostate cancer surgery a few years prior to diagnosis. Since my teen years had slight essential tremor which contributed to my nervousness especially when writing (left handed) but it did not progress, and the clonazepam helped.
Any comments are appreciated, or should I submit this to one of your doctors?