Welcome to the boards, nice to meet you
I had nightmares the first time I tapered (I tapered really fast, too fast apparently) and they scared the "you know what" out of me. I mentioned it to my addiction doctor and she told me it was completely normal.
I am going to Rehab within a couple weeks. I am waiting for a spot to open up cause I've chosen one that is in high demand (imagine that, lots of people in my position?). I too, went through (and am still going through) the "why, why, why do I do this to myself?" Why did I allow myself to take that pill when I was doing so good? Why did I relapse? Well, I don't have an answer for you, but I do understand how you feel. I made the choice to go to Rehab (with the help of my husband, parents and doctors) because I just can't stop. Believe me, I tried and I tried and I tried. The addiction has completely taken over me.
Sometimes its good to be hard on yourself, but at the same time you have to realize that addiction is a disease. Have you tried getting professional help? Does your doctor know you're detoxing? I'm just curious.
I hope you're feeling better, all the best to you.