Some of my best friends are doctors, but mercy me, they do not know how to write a letter! When my clients ask their doctor for letters (usually before I enter their case) the doctor states: “Please award Suzie or Jimmy disability benefits. I have treated them for years and I consider them disabled.” Yikes! This does nothing to help my client. Finally, it is the job of the SSA to determine my client's disability status.
What I need from your doctor is much more specific information, worded in such a way as to demonstrate your inability to function in specific ways. A general statement of disability will not work. So, let your lawyer ask the doctor for a specific report. It will certainly cost some money (doctors do not like to help a lawyer for free) but it is well worth it to prove the extent of your disability and to then win your case based upon this evidence!