Consult with a lawyer who handles property damage cases.
The above answer, and any follow up comments or emails is for informational purposes only and not meant as legal advice.
You can ask the judge in Housing Court to award you a rent abatement. You can also start an HP action in Housing Court against the landlord to ensure that the repairs are properly completed.
The above constitutes general information only and should not be considered legal advice.
Mr. Bianchi's advice is good. Take your pictures to court. Your landlord sounds like a real piece of work. If you are living in a small building with fewer than 6 apartments, you are almost certainly not rent regulated, and your landlord is not going to renew your lease. Start looking for a new apartment ASAP.