At the age of 6-7, you weren't really in a place where it was that easy for you to say anything.

Nothing to feel guilty about...you did what you could do at the time given what you knew & what you were able to do given the environment you were living in. We all look back at things in our life & wonder why we didn't handle it in a different way but we always forget exactly what we were dealing with at THAT TIME & only think about it in terms of our thoughts NOW.

He was definitely a troubled person whether he committed suicide or was killed......you did the best you could at that young age to survive what you went through. It's obvious that you didn't feel you could be open enough to say anything to your parents at the time....there must have been a reason for that. Don't worry about the past now, it's over now & can't be changed or have a "do over".......let the thought be passing.....it's normal to wonder about that, but it's not something to make your life miserable about at this point in time.