I moved in with my roommate back in December. I paid all but 250.00 for the deposits on the apartment and since have paid all the rent and other bills pertaining to the apartment. She does not and has not had a job the entire time we have been living together. I qualified for the apartment on my own. She has moved out but refuses to sign herself off my lease even though she does not live there any longer. I have tried many times to to resolve this calmly and rationally but she continues to threaten and insult me when I try to talk to her. Is there anything I can do?

Why do you want her off the lease? Right now she is still responsible for her share of the rent, whether she pays or doesn't pay, and you are in a position to take her to Court to force her to pay.

Is this a girlfriend or a roommate?

When does the lease expire? Have you asked the landlord to simply issue a new lease?