Start with the lease, what does it say are the ramifications are for exiting ahead of schedule? Normally, the landlord is obligated to replace the tenant as quickly as possible, but the tenant remains obligated to pay the lease whether they live there or not.
Next, review the California Landlord Tenant Law. You can google this and see what options may be available to you in this situation.
Finally, if you are still not certain ask a lawyer.