There was one situation where I didn't get closure for three years. When I got it finally, I moved on completely. (Before that, I was having recurring dreams about the person, at least once every few months...) I have a feeling I would have moved on completely eventually...because I have later faced worse emotional situations, and eventually I moved on completely. But it took a horrifically long time. Years and years. Not that it was consuming every day and every hour for all that time, but it was always around, always troubling me on some level. Sometimes all I need is a chance to talk things over with the person, a simple acknowledgement from them that they hurt me and an apology, then I'm completely over it. But no, obviously, you can't always get even that...often you can't even get that. It just makes everything way longer and more difficult and maybe there will always be a tiny part of you that's not really over it. At least, that's my take on it.
I would tend to think this is a very INFJ reaction (unfortunately!). Not that I'm saying you could never find it in other types. I think it's possible for any type to take a long time to get over things, or to keep thinking of more things to be upset about, or whatever. But with our tendency to overthink things, and to internalize things, and a J desire for closure - yeah, it seems very INFJ.