Hi,
I was banded in mid-January, and am still BFing my daughter. She was 16 months in Jan. I have had no problems at all with producing enough milk, despite having lost over 57 lbs in the past 9.5 weeks!
I was told it was going to be pretty much impossible to produce milk after reducing my daily calories so much, but I was determined to make it work. I just made sure to feed her as much as possible to keep my supply up, and to drink Water constantly throughout the day (besides the times around meals).
Good luck! I hope everything works out for you!