I feel sub-conciously Ennis hated the fears within himself the most. To say "it's because a Jack " is simply saying that he has sacrificed his whole life for the love he had for him, but it was in reality the fears he carried with him since 1963 that has stood in the way of a full, complete acceptance of his love for Jack and a sweet life with him. I feel he hated the control his fears had over him and how it spread to Jack, affecting him, hurting him as well. All Jack did was present Ennis with the love of his life. The rest was up to Ennis to come to grips with this fear that seemed to overcome him. " because a you Jack, I'm nuthin, nowhere" may very well have a ring of truth to it, but only in the context that Ennis's fears have kept him from having a full realization of what a sweet life with Jack could be like, if it could be at all. i think it's what he could not accept at that point. After all the years together, Ennis was making it personal. perhaps Ennis was targeting the real culprit, the fears here in himself more than blaming Jack just for loving him. How could he blame Jack for a love so dear and right?