TTC Difficulty-husband's low sex drive, and inability to get/maintain an erection.

I had to post this anonymously, as I am so embarrassed. My hubby has NO interest in sex, but wants children. When I initiate sex, more than 50% of the time his penis goes limp before entering me. He thinks performing oral sex on me is disgusting (never had any issues with my exes), and has only done it 2x in the last 9 years we've been together. I've suggested WE seek professional help, but he's declined-says he doesn't need help. He's purchased Viagra over a year ago, but that's only a result of my insisting he do so-bear in mind it comes in a pack of four. The first one was used during our honeymoon last October, and he just finished the last pill a few days ago, because I told him to take it. Ladies, I'm heartbroken and don't know what to think/do anymore :(