Still need more info...are you section 8,? welfare? SS disability, or do you work?
Most likely you will have to talk to the landlord, and show him your medical report, and help him find a new tenant, by showing the apartment, or if he agrees IN WRITING to let you out of the lease You still would be liable for each days rent plus his costs of re renting, that would be taken out of the security, and the rent you just paid..
If he re rents in a couple of days then you should get all your security and partial rent back..if the landlord is nice and understanding...if NOT you will have to sue him in small claims court to get you money back.
Most of the time courts do not look kindly on breaking a lease, but with a medical reason, most judges would be sympathetic.