I've been in your position, though genders reversed.
What (tentatively, it's early days) worked for me is having a good hard think about whether I wanted to be celibate. Whether he's worth it to me. Whether I could do that with good grace and without resenting him.
I decided I couldn't live like that. You may decide differently.
Having decided that, I talked to him. I said I had thought about it, and I completely understood - because I do, some people don't want to have sex and it is perfectly fine for them to feel that way - but I couldn't personally live in a sexless marriage.
We talked about having an open relationship. It's a hard thing to bring up and only you can know if even suggesting it is right for you.
For me, DH was willing for that to happen, but I found that even with his 'ok' it wasn't something I wanted.
So I told him that I was very, very sorry but that we would have to end.
--
At that point, DH revealed that he had a... problem... with pornography. Which is less likely, though still technically possible, for your wife.
However, I do think that when you're in the position of wanting a sexual relationship with someone who doesn't, it makes you question whether you want to be there. And I think a lot of times, the person who doesn't want sex isn't having those thoughts. It's understandable, but I think the question of whether to continue needs to be jointly solved, and the best way to do that is to present it to them. Don't make it feel like there's something wrong with her, because there isn't. It is just something you differ on, and you both need to decide whether reaching a compromise is preferable to ending the relationship. Obviously, what level of compromise you reach is up to you. But you both need to be happy with it.
Footnote: are you helping out enough around the home? Do you make her feel sexy? What about suggesting a massage, or perhaps taking a bath together?