Co-Ownership Issues

A friend and I were going to the same university, so we decided to purchase a mobile home together (with the help of our parents). We split the cost of the mobile home and taxes, etc., and we are both on the title and the lease. A couple of months into the semester, I got extremely homesick and realized that the living arrangements that I got myself into were next to unbearable for me due to numerous reasons. Needless to say, I moved back home. He has been extremely bitter about the entire situation. I am still paying half of the lot rent, half of the mobile home insurance and anything else that deals directly with the mobile home. He has spoken with his family about buying the "other half" of the trailer from me, but it isn't definite that this is a possibility, so selling the trailer is still very possible. Because of this, my mother and I were going to make a trip down to check on the mobile home to make sure that it is being kept up in case we do sell and to also make sure that he doesn't have another roommate, because we had an agreement that if one of us were to move out, we would make an effort to find a replacement roommate and that person would take over the former tenants half of the lot rent. He found out that we were coming down and immediately changed the locks on the trailer. I just want to know what my rights are considering that I am also an owner.