OP: you've been consistently uncomfortable with the idea of actually ending things, so I'm going to spell out what this looks like if you don't.
Her sex drive will not reappear. I'd be willing to bet a gigantic sum of money on this. It's been, what, six or seven years now without any sex? It's not coming back.
If you do stay with her, you're going to get very familiar with online porn. You're going to get used to snatching little windows of time in your week to watch porn and get off as fast as possible. And that's going to be your sex life for the next forty years, along with a badly dented self-image - because it'll be hard to think of yourself as attractive when your own wife doesn't show any sexual interest in you.
Actually, that's not quite true. You may cheat on her.
That isn't meant as a slight on your character. Everyone is presented at various points in their lives with opportunities to cheat - the scale and frequency of these opportunities will vary, but they will appear. The number of women who will want to climb on top of you and ride you like a horse the day they meet you is not zero, and if you haven't had any kind of sexual contact for years the day you meet one of those women, it's going to be extremely difficult to resist the temptation to throw caution to the wind. So you either avoid meeting new people as much as possible (which makes those occasional occurrences even more intense as you've developed no defences), or you maintain the willpower on a consistent basis to say no to those opportunities for the rest of your life.
So, at the risk of being a downer, those are your options. Functional celibacy (with a loaded helping of feeling undesired and undesirable), or cheating on your partner. Those are, unfortunately, the options if you don't end this.