Under nine or ten, I believe, it is possible to suppress childhood sexual assault (or at least more likely). I think it's up to five or six when the likelyhood of the memory returning shrinks down to slim to never. Of course, odds have been beaten. There are people who do have memories of trauma starting from age three.

Personally, I don't remember much of my childhood. What I do is very intermittent and I remember plenty of various kinds of abuse. However, my memory doesn't really "kick in" until eighth grade. Even after that, I have lapses in memory. Hell, I have lapses in memory from yesterday because I developed some "undetermined dissociative disorder from recurrent childhood trauma(s)". Sort of a ***** to try and remember what I won't let me remember <<sigh>>
Oh well, it is what it is, I guess. I'm working through it in therapy which is where I suggest you pursue this if you're going to, anyway. I didn't use a therapist in the beginning (I was depressed and having weird symptoms, like the ones you described but didn't see a reason to talk to some T), so when one night the smell of whiskey and someone's blue eyes triggered my first flashback, I didn't know what was happening to me and it sent me on a tailspin.

My own experience, in no way, is me telling you something happened or didn't. Only you can figure that out. I just had an elongated answer to if it is possible and encourage seeking professional advice (trauma therapist is my suggestion as they are qualified and capable of going about this the right way).