My question involves a relationship in the state of:Maryland.

Currently on the tale end of a relationship where the ex is attempting to change an agreement because they are no longer favorable to her. We moved into a townhouse on a 24 month lease, and due to the fact that my previous lease does not end until February 2013 we had to come to some sort of arrangement to make the financials work. The townhouse we were moving into cost $2000 a month in rent, so we agreed to the following:

1. She would contribute $1700 a month toward to lease, and I would contribute $300 a month until my prior lease was up.
2. I would cover half of the utilities until my prior lease is up.

Now that the relationship is over she is attempting to change the terms of our agreement. She has stated the following:

1. Either I leave the residence now or come up with half the rent for January 2013 forward until I leave.
2. I leave and forfeit my portion of the security deposit and last month's rent equal to $1995


Can she change the terms of our agreement w/o my consent? Can she force me to leave the residence? If I do leave the residence because of her request do I have a right to collect and possibly sue to recover my portion of the security deposit and last month's rent?