I feel guilty as hell reading this. I know that I was the exact replica of your s/o in my last significant relationship. I know that this drove a wedge between us. It was like a compulsion. She compromised and offered me hjs etc 4 or 5 times a day, but it didnt help because it felt like she was just 'doing me a favour'. In the end we split up and now, as a single 33 year old man, I am lucky to get anything at all, ever.
I think back to our time and I really truly wish I had found a better way to compromise or to just shut up with the begging. I am not sure what to suggest, but if you feel that showing your partner my story might be of any help, then please do. It could happen to him too, and it really sucks being in my position with my libido.
I feel for you right now, and I feel for him if he doesnt stop with the obsession. I don't know if this helped at all, but I hope it did. All the best to you.