Doubting a scenario in the past and can't trust my memories

Hello! I'm new here.

I keep doubting what I have done and seriously believe that what I have the impression of having done might not be what has actually taken place, like I can't trust my senses or memories anymore. I'm very paranoid or concerned for whether someone has done something terrible to me without me being aware of it, even under the conditions where I have been awake the whole time (i.e. not asleep, not drunk, not on medications etc etc) ... I need advice.... I haven't yet read anything similar to my case before as most paranoid cases are about an imminent future action happening to oneself, in my case is that I'm very bothered by the fact that something has happened and yet I might not have the correct knowledge of it and this thing might have been terrible ...... I simply can't explain why I don't trust my personal experience and my memories, I try to take pictures with my phone so that I'll have proof later for what I have done and what situations I have been in ... and so oftentimes when there are no pictures taken (either I've forgotten or either it'd be too strange to take pictures of stuffs sometimes when ther are people around you) I'd likely get into a panic and invent situations like "what if you think you talked to this person but it wasn't him" and "what if it was some terrible person who has done terrible things to you and you have no idea of it and think you were with your friend" ......

Dear YunSZ:

As I read your post I quickly realized your concerns are so familiar to me, it being that I read those again and again on the OCD Forum right here on Psych Central. It is a common OCD theme, to doubt your memories, to worry you did something terrible and not remembering it, or that something terrible was done to you.

atina