I, too, have pleaded with the addict not to leave.
In retrospect I think that everytime he was so antsy to get away- it was to use- but in my mind I interpreted it as him not loving me/wanting to be far away from me.
I can remember extremely distinctly - so much of the insanity- him lying to me and me freaking out, throwing punches (literally- I had become a lunatic) and then him being nasty and telling me he was going to leave. I would then block the doorway and he would say nasty things to me and make me feel even more needy, pathetic and horrible than I already did.
I am still so scarred from all of that. Even just speaking of it brought back the terrible memory, but reminds me that there is something seriously wrong with me when I am "Romancing the past" and forgetting that I am basing my self-worth on the actions of someone addicted to drugs.