Double-posting to clarify something (and because I feel an edit wouldn't draw as much emphasis since my previous post was already long):
For me, when I had sex, I'd think "Pffew! I should be good for a week or two now before he wants sex again." But he still wanted sex the next day or sometimes the next, and I would go "Well, if I have to have sex every single day, then forget it! I'd rather take the resentment." I thought he had a "sex need" gauge that filled slowly and was reset to zero at the first ejaculation.
Reading the OP I started wondering if maybe he actually worked more like me. I had a "trust and intimacy" gauge. A date wouldn't fill it up, it would just add a little bit to it. And time passing would slowly decrease it, and feeling resented for the lack of sex would drain it fast. And it needed to be full before I'd want to have sex.
With this in mind, I'm sure you can understand what I mean by "you might never be able to do it". I wouldn't be surprised if I would have needed a reset of maybe a whole year of strong intimacy, trust, etc, before I was back to normal. I would have had sex before that every now and then, but at this stage having sex drains the gauge a little too. Only when it's full or nearly full does sex increase the intimacy and trust, if it's too soon it decreases it. As a result it would have taken a really long time.
And there is no way he could have been fulfilled the whole time, yet that's what I needed.
And as much as you can love each other, at that point it's a daunting task for either party. He couldn't go without sex for a year a seem fulfilled by it. I couldn't have sex several times a week with my trust gauge near zero. And there was no medium that would have worked for both of us.
That's why I'm thinking, if you can empty your "sex need" gauge with someone else, it might help. Because the intimacy and trust one isn't dependent of an individual but each relationship. If he gets it from someone else, it won't make up for the one you're missing in your relationship. It will help a little bit at first, but it will be too little too late.
I realise I might be projecting big time here. But sex drive differences within a couple seems to be a common thing, and not one where compromises often work. If release outside the relationship helps you deal with things that are specific to the relationship, I would urge you to consider that. Provided you don't need the sex to be specifically with him, it could be a crutch until you guys have it worked out.