You know, sometimes it can be stress to not allow yourself to produce any lubricant. But, other times, it can be the pill. Or an STD. Either way, sometimes a woman just doesn't produce it that much.
If maybe he's afraid it will ruin him, then buy one for yourself, and everytime you two go for sex, tell him you're going to try it. If he refuses, provide him with medical evidence that it will not affect him in anyway. Even a note from your doctor if you want. Or maybe your doctor can help you with that as well. It could be hormonal, hence the birth control. When you're pregnant, you dry up so to speak, and the pill acts the same way in your system. Maybe if you found a birth control that has low estrogen, or a system with not estrogen, that might help. Maybe a warm bath might help, or oral sex could help too, his saliva could help.
Either way, he's being foolish. It's not him who shouldn't need to do it, it's you. Your body. And I'd tell him if he were good enough at producing his own, then you wouldn't have to worry, but he doesn't produce enough for your comfort and neither do you.
If he still refuses, then you refuse, tell him it's uncomfortable and hurts, if he still refuses, knowing it hurts or is even just uncomfortable, he's a jerk and really doesn't care about your needs. He should not be making you uncomfortable, and low to no lubricant IS uncomfortable.
Hopefully, he'll listen to you, if not, he's not worth it, don't let yourself be walked on, especially something so important as sex.
Good luck
