What Are You Ashamed Of? Abuse And Control

One of the best weapons in the arsenal of a controlling person is anything they can use to hold over your head. If you tell them in confidence that you did something in your past that you feel guilty about, that can be turned into a weapon to use against you. "Having something on you", like blackmailers on TV, is a very easy way to exert control. Because you don't want your private things to be spread all over the place, even if you fear that only on a subconscious level, you can easily fall prey to walking on eggshells around them, making sure you don't upset them, because you are afraid of what they'll do. Those with high morals and good conscience are the easiest targets for a controller, because they truly feel remorse for past mistakes, AND because the controller is not afraid of retaliation; persons with high morals are loathe to hurt another person, even if they are abusive.
EVEN IF you didn't actually do anything that you feel seriously remorseful about, they will still try this with things they think you MIGHT feel bad about, or things they think you would not want exposed, or things they make up in their own imagination, pure fiction. If the controller is a habitual gossiper, they have probably already told all of your secrets, and made up some more, just to keep the attention of whoever is listening.
If you are not ashamed of anything you have done, or when you have LET GO of shame attached to things you have done, (guilt is not shame), then they will not be able to hold things over your head in order to make you do their bidding. Facing your guilt, remorse, and shame head on, and making amends to those you have hurt in an open and direct way. is the path to finding redemption and letting go of shame. Even if the recipient of your apology and amends does not accept, or is very angry, giving them the apology and attempting amends anyway is still the route to redemption. If that's not possible because the person is unavailable for any reason, or because they are dangerous, then the next best thing is to tell someone else what you did, and make amends in another way; but ONLY if the person is honestly unreachable or dangerous.
 Remember that every single human on the Earth makes all kinds of mistakes, and has all kind of "flaws" and "faults". If someone is holding something over your head, or trying to use something you have done or do to make you look bad, or treating you as if you are not as "good" or as "worthy" and therefore don't deserve the same normal courteous treatment as anyone else, they are a controller.