He's not asexual (as someone above suggested) because he's quite happy to initiate and have sex. He just doesn't give a shit about your experience. Not one, tiny shit.
You already know that this marriage is killing a part of you. The thought of this over the next 20-30 years is unbearable.
So get things ready. Do you work? Can you support yourself? This is really important because, psychologically, if you can't can compound the feeling of worthlessness you get from him. It also makes you free to choose whether you stay or go.
Then get him the book "She Comes First". It is a good one. Simple language, guy to guy. Tell him you're really unhappy with your lack of orgasms in sex. Be serious in the discussion but calm. Check if he reads it - not by asking, but look at the book, is there a bookmark, is it moving. Do not argue about it. At this point there's nothing to argue about.
If he reads it, good start. He needs to then put that into action and discussing it would be a good start. At no point should you let him think something is comfortable if it's not or arousing if it's not. You can just say "that's not working for me right now" or better still, guide him to do it better "I love that harder, softer, to the left, right" etc. He should respond to what you like. Don't lie there having him experiment with your body or treat it with anything other than full respect. His goal is to make you feel pleasure in the beginning - orgasm can come later - not like you're a participant in a live anatomy lesson.
If he's not bothering to read it, it will probably drive you nuts - because the pain of him not giving a shit about your sexual pleasure will be triggered. But you will have an answer to whether this is to be the rest of your life or not. And then you have the control about what you want. Do you choose to accept no sexual pleasure or intimacy ever again or do you give yourself the chance of that experience?
You can also go to specialised sex therapy but I'm betting he won't do that. There is also a Relate book about sex that has good exercises in it at the back but I think your DH needs She Comes First to get the message across. Even if he doesn't read it, an important message has been conveyed.
And at no point in this should there be thoughts about "I can't break up my family because I'm not getting good sex". Unless you feel this life is one you want for both your daughters. If you choose not to accept being treated like a glory hole (harsh but that's about the sum of it) for the rest of your life, your DDs will still have a relationship with their DF (unless he's a dick about that, but that's not your responsibility). They will also have a chance to see their mother feeling fulfilled and happy. They have zero chance of that now. Ever.
And don't downplay the significance that extreme lack of physical intimacy over years has on all areas of your life. This isn't about lack of sex. It's about not being cherished. It's about living day in and day out with someone you know doesn't care enough to make you feel good, who not only won't ever put your physical needs before his, but completely negates that you could possibly have any. There's something about sex that is completely underestimated in our culture (maybe others too, I don't know). There's the idea that we don't have a right to it, or should be able to do without it, other things are more important. And that is doubled if you're a woman. But there's a lot of faulty thinking in that. So my advice is just not to go down that route: you're not asexual, yet you're basically being expected to live in a situation as if you were (because him penetrating you doesn't exactly count).
Also, the fact he was a virgin is a bit of a red herring. Everybody was a virgin at some point! After he wasn't a virgin, then what has he done?
Maybe your DH will be different than mine. Mine didn't change. It broke me. But, then I ended up meeting someone else who brought me multiple orgasms - when I believed my body couldn't ever do that because it was so unaccustomed to anybody touching it. There's no easy route ahead of you, but there is a possibility of great sex if you want it.