I sympathize with your dilemma friend. You may have to take a huge risk and come outright and tell the doctor point blank like you did in this post and see what his reaction will be. I know the subject of disability is a delicate topic to broach with your primary care doc. I told my doctor I was simply unable to continue working due to my medical condition and ask him if he would be willing to fill out any disability paperwork for me if need be. I had another doctor so this guy was like a secondary. I also had to discuss this with the primary mental health doc. These things may be very uncomfortable to talk about but you must if you are sick and may not be able to continue working much longer.
If you lose your job do to attendance or poor performance, your STD and LTD go out the window. You then find yourself still sick with no income to support yourself or treat your medical condition.
Here is something you might consider. Call around in your local area some lawyers who represent SSDI claimants. Tell them you may be looking at filing a SSDI claim if your disability prevents you from working further and ask them if they have worked with any doctors in the local area that have helped past claimants of theirs. They may be able to recommend someone to you. STD and LTD are valuable benefits available to you if you become sick and can no longer continue working but these benefits are worthless IMO with unsupportive doctors. You are not doing anything wrong. You are simply sick. This is what I told myself over and over after working for the same company over 20 years. I saw possible STD/LTD in my case a year prior to it happening because of chronic mental health problems that I have struggled with for decades. If I did not have these valuable benefits available to me when I became too sick to continue working, it would have meant financial ruin for me. The beauty of LTD is that while you wait on the long SSDI approval process, you have incoming income to survive in the meantime. It is a valuable benefit that you don't want to lose even tho the DI carriers can sometimes be a PITA. Take care my friend. You must have this talk with your doctor. It is critical that you do so.