I am all for honesty and am convinced it is essential
for any kind of meaningful recovery from addiction. However---I do NOT
recommend spilling your guts to the board of nursing without consulting an attorney first. When I got in trouble years ago, I foolishly thought that if I just admitted what I had done I would get "help," whatever that meant. How sadly naive that was! All I really got was severe
Any real help I got for addiction issues was in spite of, not because of the consequences I caused myself with my board of nursing. That being said, I do live in one of the most punitive states with regard to addiction, with no alternative to discipline program, so maybe your state will be more humane. Mine sure wasn't.
Be honest with your sponsor and therapist (assuming you have confidentiality--I did not at the time), but be very careful with the board of nursing. They are there to protect the public, not to be your friend.