Aimless Ideas: Feeling terrible and then not

What can I say? Everyone makes a decision that will utterly have a consequence either instantly or forever, maybe even both.
Whatever.
Me?
I have no idea, possibly my actions are to be forever remembered or not, either way it sure was instant, as far as I can tell. Regardless, we must all move on unless we are to live in a single moment forever. Without being too easily specific and making you not think and then have the satisfaction of "OH! that's what he's talking about." I made a choice that affected another person, and now I bear witness to what it has caused.

But what exactly does that even mean?
I know how it has affected me, without a doubt, I felt pretty awful, and definitely wished not to have done so to make me feel like that, but what exactly do we feel awful for?
Is it because it didn't go as we wished?
Or is it so because the person we affected might feel similarly? Maybe I am too much of a person who thinks about how others think instead of myself, and lately I think that's actually just right on the mark.

Perhaps it is okay to be selfish about things, but of course not in a manner in which to be a total disregarding person and say to someone "Well, fuck off. You didn't want it that way." Not at all.

But instead to not engulf myself into another person so much that I forget what makes ME happy, what makes ME still alive, that whatever happens, it'll pass over and I will laugh about it in a year or so with said person.

Maybe not that well, who knows? Perhaps what I have done is irreversible and I will forever only lament the fact that I did something to alter a friendship or perception of myself to another person.

But what's the point of worrying about such things?
Misery loves company, don't just fucking give it company like it's fucking Christmas and you got the Secret Santa at your shitty job at the local law firm office and the items on the list are

A) Sulking Partner
B) Crying and Remembering the 'Good times'
C) Karaoke with shitty 128kbps MP3s burnt on a mixtape

I cared (still do) about this person, obviously, but if we were to say I could go to the 'old' perception, would this person want me to be miserable about it? To want to just imagine every moment a living hell?

I sincerely doubt it, so in whatever fucked up way, in honor of the way things were before (this is a loose term, things don't change only perceptions goddammit) I myself will not feel awful for it, and maybe with time and patience this perception with another person can be similar to how it once was.

Of course unless it's something REALLY awful like rape or some such, yeah you, I knew you thought about that. Sick fuck.

EDIT: Fuck, I might have done it wrong, time to fix things!