[pseudo t-bone]

while you have a duty to make payments under the lease, your landlord has a duty to mitigate its damages once you breach the lease. even though you reached any oral agreement with the landlord, it doesn't mean much - all agreements dealing with real property have to be in writing.

if you had simply left, your landlord could recover from you the rent you would have owed until a replacement tenant was found plus the cost of finding the replacement tenant. basically, you offered to pay the landlord everything it would be entitled to.

it's up to you how to proceed now, but it wouldn't be a bad idea to send a letter outlining the agreement, noting that you have paid for a real estate agent, and then stating that you feel the landlord has had a reasonable opportunity to find a replacement tenant, and you will not be making any more payments. problem with this is that the landlord could potentially sue you for breach of lease damages in excess of what you have already paid. depending on the lease, the landlord would probably be able to recover attorney fees from you if it is successful.