How do I deal with His controlling and mean parents?

My boyfriend and I have been together a little over a year and I love him very much. We are sophomores in college and his parents try to control every moment of his time, and he doesn't really stand up to them. It is summer and we live 15 min away from each other. I see him about 2 or 3 times a week and his parents are complaining that they never get to see him. They say I am making him do things he doesn't want to do and taking up all of his time. They sarcastically told him to (not think about marriage quite yet). I am very hurt by these things. They say it is fine if I go over to their house and see him but he can't come to mine. I can't do that! I have a life and things to do, I can't always drop everything to go over there. The reason he doesn't fight back is because they pay for his college tuition and he doesn't want to lose that and he doesn't want to have to choose between me and them. I really don't know what to do, I'm so tired of never getting to see him and crying because of his family's comments. I love him so much. Please help if you can.