Therapy. I'm sorry to put it so bluntly, but it's a very VERY heavy bit of trauma. If it wasn't you wouldn't have repressed the memory for so long. You seem to know just what it is you need, and why it's so hard to get to sleep. Talking to a therapist would be the next step...and they would know what to do to go about getting you to that place of acceptance and peace.

For what it's worth, I'm sorry for your loss. The loss of the man you once knew as your father can be so deep....so entrenched within us. (( I never knew mine until just 4 years ago. Never knew how much I had missed out on. )) My thoughts are with you, Shady.