I've never heard of a swollen bartolin's gland but I just looked it up. From what I've found they usually develop on the lips of the labia, and not inside the vagina. They are also painless, unless they become infected. If it feels like he's hitting something inside, my guess would be that it's probably not that, but again, I'm not familiar with it so I could be wrong.
What you're describing sounds different than what I had, mine was more like a burning. Usually for me when it feels like he's bumping into something it's my cervix. Your cervix changes positions at different times throughout your cycle, and can make sex very painful if it's low and he bumps into it. I've found that certain positions are just painful at certain times. If he is hitting your cervix, this is usually felt as a sudden, sharp, stabbing pain like he is jabbing something, and can also cause stomach pains during and after sex, sometimes even for a day or 2 after. And if he's consistently hitting it, he could bruise it and cause sex to continue to be painful. Have you tried different positions, going slower, and having him not go as deep? You should talk to him, I'm sure he cares about you and doesn't want to hurt you. If he knows what you're feeling then he can try different things to try to make it not hurt, and who knows, together you just might find something that works. But if it really hurts, ask him to stop, I'm sure he'd understand. Plus if there is something wrong you could just be making it worse by bearing the pain. If you've tried changing positions, going slower, and having him not go as deep, and if it doesn't feel like normal bumping-the-cervix type pains, you should definitely get it checked out. Good luck!