Something happens that reminds you of your past. If your memories are of good times in your past, then that could be considered Nastalgia. If I was going to name an antonym for this use of Nastalgia: Regret. Not having done all that I could have done. (The problem is not having “not accomplished” something, but rather… going the extra mile vs. running until you pass out.)
Immagine if in your past everything that you did wasn’t good enough. Every memory you couldn’t win, succeed, you were always one step away from reaching your goal and failing. Even when you reached the goal there was a reason, an excuse for the situation to not be … happy.
It’s really hard when you think you have good memories, and the memories might give you good feelings, but you’re scared of them. You’re scared because you know that if you go back to that person they will hurt you, and you know you hurt while you were with them.
I hate my memories, but that doesn’t mean that there aren’t any good ones. Listing events as they come feels as though it helps. “This will be a good memory, I was proud of myself and what I accomplished.”
*When my father drove an hour to take me to a horse riding lesson.
*I had this one really great friend, and although it may be in the past now – I was happy. It was the only time in my life that I’ve felt as though I could be desired, and because of him I learned self-confidence, and self-worth, and I found that I could work to actually become the person I want to be.
… When I don’t wake up in pain. I’d kill to get rid of that pain.
I have some good guesses that should help. The only problem is going through with the plans, and not just filtering them out.