Ever since about 3 years ago, during my freshman year I have been experiencing disturbing dreams. They don't feel like dreams though and I don't know if they are or not. When I fall asleep sometimes, I find myself being attacked, like something is chocking or trying to squish me, but the weird thing is that I am in my bed and I can see everything but I cannot move. Am I in the presence of a demon?

No.

I doubt it but the feelings your experiencing may have to do with the dreams themselves not because of a presence or demon. You could have stopped breathing for a short time within your sleep that may have caused you to feel like your choking. The dreams themselves could have been promoted by a experience that happened to you that causes to have these dreams

Sorry if this doesn't help