Based on the information you provided, it appears as though the lease provides that either party may terminate the lease within 45 days of the expiration of the lease. You have correctly stated that you received notice of the rent increase after that 45-day period. Based on what is provided above, nothing explicitly prohibits the landlord from setting a new rental amount. However, you would be able to argue against a new one-year lease term, as you were not given the appropriate notice regarding the increase in rent.
You should attempt to contact your landlord to work this issue out amicably prior to retaining counsel and/or court appearances.
The answer provided herein does not constitute an attorney-client relationship, and should not be construed as case-specific legal advice. For more detailed advice or information, please contact or retain a local attorney.