on the verge of frustration.

me and my boyfriend have been knowing each other for 7 years. we just recently started dating this year and are coming up on our 1 yr mark in december. in the beginning we were So satisfied and loved our sex life. once we moved in together though, things have not been so great. We now only have sex maybe once a month. Now we both have gained some weight since weve been living together for these past 6 months. I am still very much attracted to him and have a very active sex drive, but he says hes not confident enough in his performance or himself to have sex. at a point in time i wondered if it was actually me, but im clean and i fix myself up for him and even initiate sex to make him more comfortable and interested but nothing i do increases his interest to have sex. he actually says its not that he isnt attracted to me, its him even though he says i beg him for it. I would never cheat on him but im at the point where im believing theres more to it then him just not feeling it. i mean everyone gets horny and wants to feel the touch of another person. Am i just over reacting or should i be worried?