Interesting polls, both of them! Yours anthony and upstream's. At first I didn't think I could even vote on this one, bc I was confused with the definition of primarily. Had been thinking it was meaning most significantly, and for the life of me cannot choose between impact, importance and severity of traumas. Once, I looked it up in the dictionary I read: pri·mar·i·ly: 1. chiefly: mainly or mostly, And 2. originally: originally or at first.
So now going on the 2nd def. (originally), well that would be my father. Responding to the 1st def., and interpreting that as most chronic in nature, well then that would be my mother, and her lover (step-dad).
If I added in most debilitating and longstanding results, that would then be those already mentioned in addition to my sister, a stranger, and later an acquaintance. Those additions (those 3 in 86') seemed to have been a catalyst for complete breakdown and debilitation.
Considering everything will conclude and select: Primarily- mother, father, sister, brother.
***Though I don't have any brothers, I always fantasized and wished I did have an older brother (fantasy: the heroic sibling and brother, that would've, could've, should've, might've taught me and protected me throughout. ,,, as well as caring for and standing up for my sisters when they were very young).