is being attracted to incest normal?

i dont know if its just me or others too feel attracted to their brothers or sisters sexually. in my case it might have been triggered by a childhood experience. i always hated my little brother who is almost 2 years younger than me, and used him for my experiments. and it was him with whom i first tried kissing and fondling. i was then 7 or 8 years old and was only copying what we saw adults do in the tv. of course when i was 12 years old i finally learnt what the hell adults do in that position, and that, siblings must never try those things. though i did that unknowingly, i have since then suffered this self hatered, guilt feeling. now i m 21 and though i tried dating some guys, i could never go through that "physical'' part. it was like re-living that childhood trauma. should i just go to a psychiatrist?