M.L.
I'm so happy to hear you are so dedicated to breastfeeding! Great job mom!!
I think I would follow Lisa's advice and ask in the main office about a private place, or possibly an understanding professor. Maybe someone would be willing to let you borrow their personal office for a little bit so you could have a comfy place to sit. As far as cleaning goes, whenever I had to pump away from home I would rinse it off as well as I could and pack it all into a ziploc with a cold freezer pack so it wouldn't get yukky before I could get home to properly clean it. I also had 2 sets of parts, and you may be able to contact the manufacturer of your pump to get more supplies.
There is also the less fun option of getting a cigarette lighter plug adapter for your car and you could do it in there. They are available wherever tools are sold, my husband has them in all our cars for various reason. I know it's not ideal but at least it is your own space and there is less chance of someone bothering you to give up your room.
Good luck and keep up the great job of nursing your son, the benefits are so wonderful for him and you!