Your landlord is essentially asking you to leave on your own without him or her having to initiate the standard eviction proceedings. Breach of quite enjoyment, as its known, basically means that you have done something that makes it difficult for others to live near you. (Its slightly more complicated, but that is a simple way of putting it.) Usually this can be domestic violence, loud music, selling of drugs, frequent police visits, etc. Your lease likely provides that the landlord can terminate the lease for this reason. It sounds like you should visit a a landlord/tenant attorney and bring your lease and any other documentation you have. If you would like to set a free consultation with my office, please feel free to call or visit: www.holmespoirier.com.
The prior answer is correct, but beyond that, if you are current with your rent, you would not leave until 15 days of the following month, if you wanted to get out of the lease. Beyond that the harassment claim first requires a demand for you to correct that behavior, before calling it a breach of the lease.