Assignment And Assumption Of Lease

Earlier this year, I took a lease on commercial space in New York to a friend set up a grocery store. His lawyer made me sign a surrender and take the form of lease he said was necessary for my friend to be able to apply for licenses (tobacco, beer, etc. ..) on its own behalf . However, the prosecutor did not explain that I had the written consent of the owner to sell my lease. Until now, the owner is not aware of this situation and the payments are in my name only.
Is the assignment valid? What can I do to correct the situation and to cancel or terminate this mission?
Thank you and best regards,

Single, never sign anything else for someone else, unless you're willing to pay your credit or who have ruined.