I know some ppl don't have this happen, but this happened w/ my DH.
Our drs would not write down that they felt my DH was disabled. Too much paper work, I guess. 
My DH was contacted by SSD to go to appt w/ one of their drs. We went to the appt w/ the same sheets of paper we bring to our dr appts. It lists ALL of my DH's conditions, meds, procedures, drs, etc. Their dr looked at the list, looked at my DH, looked at the list again. The dr then asked my DH to stand, examined his eyes, his gait, his feet, etc. He was very polite and kind. He said he would be turning in his report by the end of the wk.
My DH was approved for SSD due to that visit/report. I hope it goes that well for you.
But if it doesn't go smoothly, by all means, contact an attorney. That is what I had to do, after my rejection letter. I never had the SSD dr exam, just a hearing where the judge could see I qualified for disability.
Good Luck!
God bless. Alice.