I agree with being completely honest to the doc. Even if you think your benefits might be changed, just talk with the docotor about it, he/she is there to help you in anyway he/she can.
I lied to doctors for years about my drinking. When I was admitted into the ER with an inflammed liver at first I still lied about! It is hard to come clean, but it is such a tremendous relief when we do. Good luck to you.