My Husband No Longer Desires Me?

We've been married a little over a year and he is an every night alcoholic who prefers beer over me. You'd have thought I would have known this but we married within 2 months after meeting. He was extremely loving and affectionate while we were dating. I met him last January and broke my right knee and ankle on January 30. I was in a cast and wheelchair for 6 weeks and physical therapy for 6 more. Even during that time, we managed to find a way to make love. Then his 2 adult daughters moved in for 2 months and our life became more days apart, he goes to bed early and I don't. They moved out and 3 months later, his 2 sons moved in and are still here. He had been slowing down on lovemaking and now we are at a complete stop for going on 3 months. I have talked to him lots of times that I am hurt and feel he doesn't love me anymore. He says he's sorry, he simply has no desire at all, for anyone. I even accused him of having an affair with someone at lunch cause he works a block away from home but he said "hire a PI, I'm now guilty of anything." He had a blood test and he's low on testosterone but he's stopped using the gel. At least I have my vibrator but we know it's not the same. I don't want to call it quits after a year but I didn't sign up for this and would NEVER hurt him in this way. He has broken my heart.