Something happened to me when i was young. started dreaming about it and felt like i was being touched by him during flashback today. is this normal?

Flashback are just: that--revisiting an event with some feelings. This sounds like a job for a mental health pro, presumably one skilled/experienced in the areas of sexual trauma. Look for a therapist who is EMDR trained. Probably should work with a female therapist. A support group would help, and there are lots of good biblio-references. Here's a good one: "The Courage to Heal." (do a Google search...)