I was 3 and a half or 4 at the time, and I remember waking up from a nap all undressed, with a man sitting on my bed rubbing me (I cleary remember what he was wearing, but don't remember his face, not to get into detail but it escalated quickly and then it was over, he talked for a minute but I was totally zoned out and couldn't understand what was said, he left and I curled up and cried for what felt like hours.

I remember when my mom came in she kept asking what was wrong and I said nothing, but was still really shaken up. I remember a few times when I was little it was really hard to hide, like when watching some movies and TV shows, but I seemed to guard it with my life. I had nightmares every night when I was 8-11 and now get flashbacks and panic attacks when the subject comes up or someone stares me in the eyes.

My question is, if I was raped wouldn't it be impossible for my parents not to notice, wouldn't I have internal damage and bruising?

First, the issues with memories, at that age, they can be confusing, from things we see, and hear. Depending on many factors, no, the parents may not "tell" unless they were looking for it. And the fact you were not telling anyone.

The issue now, if it happened, or did not happen, you have spent your life, believing it happened, and it is effecting your life. You need professional help to deal with this. I