The StassiNet

"Disappointment is the feeling of dissatisfaction that follows the failure of expectations to manifest. Similar to regret, it differs in that the individual feeling regret focuses primarily on personal choices contributing to a poor outcome, while the individual feeling disappointment focuses on outcome.(Wikipedia)"

You start out with something that seems so perfect, like it was meant to be, nothing could ever go wrong. Then suddenly everything starts to turn, one by one things start going wrong until you realize it never was perfect it was just your frame of mind. Sadly its when everything comes clean and you notice each fault for its own that you grow from it. Each piece of you that feels like it is being ripped out, slowly heals and you learn from each mistake, the same for when someone rips part of you out. You grow, you learn to accept what is wrong and put the pieces back together to make what you were whole. Though you are missing pieces you still work.

"Regret is an intelligent (and/or emotional) dislike for personal past acts and behaviors. Regret is often felt when someone feels sadness, shame, embarrassment, depression or guilt after committing an action or actions that the person later wishes that he or she had not done. (Wikipedia)"

Believing that continuing the same action will present a different response, and then realizing that it never will your just insane for believing that. You regret a decision but you make the same one over and over again, and feel stupid each and every single time you make it. You wish somehow in your mind that it wouldn't turn out that way, or you could choose a different option and realize it wont work.