If both insist I need to stay against my will, what are my options?
Tell 'em to cram it. You're a tenant-at-will, and have thee right to terminate your tenancy at any time with proper notice.

The length of your contract is one month at a time. To end your contractual obligation, you need only give proper written notice - 30 days notice. That's it. The landlord may not demand that you get your other roommates to give you permission to move, nor may your roommates demand that you find another tenant, nor may they demand that you continue to pay rent after you have vacated the unit.

If the landlord wanted to invoke the provisions of an actual fixed term lease, he should have had you sign one. As it stands, he did not, and he's out of luck, and so is your roommate.