You both want and need different things. You did have sex in your relationship, but now your relationship is established, he no longer feels he needs to pretend to want it or enjoy it. He's happy as he is.
But he doesn't matter here, you do.
Like many you crave physical contact, and that's fine. But you must really look at him and understand him, because he's showing you who he is. This isn't a phase, it's him and it's how life will be with him.
You're too young to settle for this. And no more being grateful that 'he took me and the kids on'. He should be the grateful one for having you.
This isn't a proper relationship, and you must settle for no less than what YOU want.
Tell him that it's a deal breaker for you. Tell him you'd like to maintain your lovely friendship, but be prepared to lose him as a friend.
Can you really imagine being with him, in the same situation, in five or ten years time? Your best years are ahead, spend them wisely in a relationship where you feel cherished and valued, not rejected and sad.
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