Sorry to hear about your problem. It's terrible when one spouse completely disregards the other. Yes, your husband's problem is medical. But, it is a problem that is treatable. If your husband had testicular cancer and the treatment that saved his life left him impotent, then it's not his fault. At this point, refusing to seek treatment because the last treatment didn't work immediately is his fault. So, let's move on to your options.
First, you could have a secret affair. This isn't a good option, and you've said you don't want to cheat, so I'll just leave it at that.
Second, you could divorce. You have cause. You've only invested two years in this marriage and I presume you don't have children together. Yes, you love him. But, he doesn't love you as much.
Third, you could tell him that you plan to have an open marriage to meet your sexual needs. Right now, he thinks your options are to masturbate, or abstain. You could disabuse him of that notion. You have other options. Tell him you just want to give him advance notice so that he's not taken aback if one of his friends sees you coming out of another man's apartment late one night, or early one morning. The good thing about this option is that it might shock him back to reality.The bad thing is that he might give his blessing, which you may not be prepared to carry out.
Fourth, you could begin to deprioritize him in a similar way that he is deprioritizing you. Of course, you can't refuse to have sex with him. He doesn't care about sex. But there are things you do that he does care about. If you cook for him, stop. Cook for you and tell him to make himself a sandwich. If he balks, tell him tough. You're no longer interested in providing for his needs. Run the 180 on him. The 180 will help you distance yourself emotionally from him and prepare for life on your own. Sometimes, it has the added benefit of showing the other spouse that he is about to be alone, which can spark a sudden change in behavior to avoid divorce.
The Healing Heart: The 180
You may have other options, but that's all that come to mind immediately.
Good luck.