Maybe something positive having more to do with your own personal growth and determination (as opposed to negative energy aimed at a particular organization riddled with controversy). This growth can represent broad growth and embracing of a wide range of interests and involvement rather than limited to an obscure belief system.
Positive energy, Law of Attraction type of thing?
A phoenix rising? A flower blooming? Chrysallis??
Maybe mark it with the date of your official decision to end affiliation and take charge of your own life.
Maybe try Google Images for "personal growth tattoo ideas".