How do you deal with pain, misery, being unsatisfied, not being able to get what you want?
One is acceptance. The worse has happened, accept it, let it go. Then there are those who find it better to repress it. Repress the anger, repress the pain, the guilt, whatever load there is that's weighing you down. But repression is always temporary, it can never be a permanent solution. The skeletons are going to tumble out of the closet some day.
Acceptance may be permanent, if you are strong enough. The point is, the mind is such an untamable object. Thoughts just run haywire. But at the same time, it is very mouldable. You can hold on to whatever you think is important, without questioning your decision. But a point comes when it starts to choke you. That is the time to re-evaluate your choice. Do you really need to hold on to things that you know will bring you pain? The rational answer is obviously no. But, still you do it. That self-destructive, self-pitying streak in you, it is unrelenting. Bittersweet.
But when you do overcome that, you wonder what made you hold on to something so meaningless in the first place. Because the thing about life is, whether you like it or not, it goes on. And you will have to move with the current. Stagnation is impossible: it is against the very fabric of the elements the universe has been moulded in. It is against our nature. Holding on will only cause misery.
The present will always be the thing that matters the most.