A 'suppression' is not normally the result of any such evil entity. It is simply caused by a person who has different intentions than myself, expressed persuasively, so that I now feel suppressed, depressed and stressed.
The other person is not necessarily evilly intentioned toward you, or anything of that nature. They may be well intentioned and often are. They merely have to cross your goals and purposes without malice or forethought and for the best of reasons. As someone once said: "The path to Hell is paved with good intentions and roofed with tears." How right he was.
So what is suppression? Suppression can be defined as being forced out of one's own time and space by another's purposes and goals. One moves out of one's own identity into the time and space of another's goals and purposes in order to handle the situation being presented - instead of saying "Get stuffed" or something more diplomatic and going on with what one was intending to do in the first place. In other words one didn't maintain integrity.
There are two directions in which one might move - toward or away from. Either creates the Catch 22 situation that is suppression. One can align with the other's identity, which their goal or purpose imposes, or one can resist the goal or purpose and become another identity - but not one's true self. But there is another alternative - one could maintain one's integrity, just be oneself. This also means taking responsibility, acting on the basis of a clear sense of one's own identity, goals and purposes.
For example, a proud father wants his son to become an engineer like himself. If this is not what the son intends he either complies and makes a lousy engineer and is subject to suppression throughout his life by having to follow his father's vocation. Or he resists this persuasion and becomes something quite the opposite, such as an artist, but he doesn't do well at it this either because it was set up in opposition to his father, not as something he really wanted to do. So again that person feels continually suppressed by life. His problem is that neither way can he be himself, a Catch 22 situation. Compliance or resistance generates constant emotional charge in the person's life that doesn't resolve. Its a locked situation. He may - and normally does - hide this situation from himself and he may have no real idea who he himself is, what he really wants to be and do in life, what his true goals and purposes are.
Notice which people in your life make you feel good and which make you feel bad. When you find yourself feeling limited or put down or depressed in somebody's presence, write down who it is and exactly what happened. And when you feel uplifted and in a good mood in somebody's presence, note down who it was and exactly what happened.
Look for specific reasons for your feelings in those situations. What is the difference between the people or situations where you feel good and the ones where you feel bad?
Isolate what is going on. What are your intentions, likes, dislikes, purposes and goals that are being suppressed. They may be being suppressed by yourself now as well, but originally they were aspects of your own identity that were effectively suppressed by another's influence. Or that suppressive influence - perhaps with the "best of intentions" but not your intentions - may be continuing into the present.
Just recognizing the truth of one's current situation will help to free it up. Work out how you can organize your life to minimize the negativity and reclaim your power.
Remember that the situations in your life where you feel at effect or a victim are something you are doing and creating by yourself. It might appear to be other people's fault, however, we are the ultimate cause of our lives.
When I was a child, parents or teachers were "always right," and I had to conform to their rules. They had all the power. So the choices left would be extreme, like running away from home or jumping from a bridge; or being unquestioningly obedient and gradually losing touch with myself; or just being thoroughly depressed. How these experiences can be resolved? The past cannot be undone but I can change my interpretation of it. From a mature, adult point of view I can show my inner child that perhaps another choice remains: to understand that my parents or teachers may have been misguided but were acting in what they thought to be my best interest, so instead of feeling resentment I now have the choice to instead feel a little more understanding and empathy. And then I have the choice to forgive them, a choice that I did not feel I had then, and to learn some valuable life lessons from the experience.