Polyamory

Where do I begin? Blogging seems to have become such a natural and common place activity. I am so private a person I have never considered a journal nor diary . However I feel compelled to talk about my inner most thoughts and personal demons in such a public forum.
Am I a polyamorist? That's what I am asking myself. My wife has confessed to me that she is and all I seem to be focused on is how I am not enough. Now we have enjoyed an open relationship for many years. But now to evolve from open to polyamory scares me. See I am the typical unflappable personality, but I can't seem to shake the feeling of somehow I drove my Dear Wife to seek out others. DW, to her created, has repeatedly tried to aleviate those fears. But now I am driving her away with my emotions on this matter. I tell myself to just let it go and trust in us but jealousy seems to have taken it's toll on me and her to a point of ending our relationship.
We argue about stuff like if she meets a man, she feels like I ought to be buddy buddy. I explained to her very distinctly that I would be lukewarm at best. I promised not to taint but I know I would never fully warm up to another guy. We always talked about another woman fulltime, even before we discovered the term polyamory, and after awhile i agreed to that. I liked being open. I liked the non-committal aspect of being open. Though I may felt the twinges of jealousy then I always dealt with it. Now I feel like everything has become bigger than me. Bigger than us. This makes normal marital issues magnified to tremendous amounts where once they were easy to deal with.
DW and I have been fussing but I admit I am the antagonist in this story. I want, need to break this cycle of negativity. But like some addict I seem bent on trying to prove that she is only doing this because I am not enough and how do I make this right. Problem is that I am enough and she needs these other dynamics to have a fulfilling life.
So now I ask myself am I polyamory because in learning more about her I have been forced to learn about myself. DW would always say even in being open I am the one that always gets more emotionally involved and that in reality she was the one who had to learn to adjust and be poly and I may be fighting my natural tendencies for fear of a lack of control. Lack of control(jealousy) something I thought I truly conquered years ago. Yes I am a polyamorist. But this jealousy thing is kicking my ass.
I have to admit getting these thoughts out of my head has been a little theraputic. Think I will do this again.