The questions “what if” and “what could have been” are the only real source of pain at the end of a relationship. None of the infinite possibilities or probabilities are responsible for the sadness, depression, regret or anger that you feel. As emotional beings we have to quantify loss as the direct result of something we did or didn’t do; cause and effect. We go over all of the things we feel that could have gone differently to prevent the heartache and then torture ourselves with hypothetical scenarios that fix the hurt.
The reality is that the past can never be repaired. Feelings cannot be restored to prior levels. Actions or inactions cannot be undone. Arriving at this conclusion takes a lot of time and a heavy toll on a persons mental health. This is the way we live. This is the way we learn. Building walls around emotions only postpone the inevitable breakdown that you need to have in order to move forward and grow.