stop being result oriented.
the hand you folded ended being the best hand and you lost out on a lot of money/chips. so, you're upset because you think you made a bad decision by folding, right? but what if the hand you folded didn't hit anything or would have lost to a better hand? would you think you made a bad decision by folding then? if so. or if how you feel about your decisions is based on the results you see, you're being result oriented. you're letting the outcome of your past decisions affect you.
now, was it a bad or good fold? i don't know, i didn't play the hand, i wasn't in your situation. however, there aren't a lot of hands i'm calling with for 50% of my stack preflop.
how do you get over your decisions?
one, try not to regret any of the choices you make. whatever line you take, there should be a reason for it and that reason should be based off what you think is the best decision at the time. that's not to say it'll always be the correct decision but, at that moment, you're making the decision you think is best.
when i play, no matter what happens, i happy with my choices. it doesn't matter if i decided to 3bet jam jj for 40 bbs and run into aa, or i decided to check/raise an oesd + flush draw + over cards in a key mtt spot and completely brick, or i decide to jam j7s in the bb for 16 bbs when 5 other players limped in. whatever happens, happens, and i'm happy with my choices.
two, improve your game. remember how i said you might not be making the correct decision, but the one you think is best? well, read up on those key spots where you do have to make big decision and learn what the best decision would be. so now, not only can you make those big decisions, you can be confident in knowing you're making the more profitable decisions as well.