How do I remove myself from roommates mortgage?

I'm sorry to hear about your difficult situation.  If your name is on the mortgage, then your name must also be on the deed.  You can either both agree to sell the property and pay off the mortgage; he can refinance the loan and take you name off the deed or you can inititiate a partition action with the court to force a sale if he won't cooperate.  I'd want to see all of the pertinent documents before giving you definitive advice.