I have so much regret

What was it, was it, and how much of what happened was under your control? Besides, it's not even bad that it was. If you did not go through the experiences you regret today, then you would not be the one you are. You would not be YOU. If you reject, if you try to cut out of yourself the dark side, you lose your integrity, your being becomes incomplete. And who wants to be a half man, no matter how good? Who wants to live only half a lifetime, however happy? It would be just as unobtrusive, as ugly, as a contrastless photo.

The past is a memory. It's what you imagined that happened, it's your version of events, not an objective history. In fact, there is no such thing, it is always an interpretation, even from the perspective of other actors. Your history is a sum of incomplete and distorted episodes in which you are the main hero and the basis of your feelings. Even your regrets all come from those memories without happy endings. Fortunately, this is a story you could rewrite, just as the history of mankind is rewritten without ceasing as civilization evolves and gathers more and more data about the past.
You could collect all the memories of your memories that now make you uncomfortable and, with the archeologist's attention, regret it and regret it in the light of what you have learned so far about life. Review each episode in which life seemed unfair to you and contemplate how it fit into the great but incomplete puzzle of your life so far. Analyze to what extent what you treat as a failure was actually but a disguised blessing, an unwanted change of direction that puts you to self-realization.

So much about the past. What to do next to avoid regrets? Imagine that you are a tourist whose bus stops near a bazaar full of strange colors, sounds and smells. Go down and admire the view, glad that you have escaped the inside of the building and that you finally have the opportunity to relax and astonish your curiosity. You start to dive in the atmosphere of the place and take pictures full of delight. Local people surround you with various goodies, maybe you start to talk to them. But all this time, no matter how fascinating the scene is, keep close to the coach so as not to miss the departure. Otherwise, the joy of escalation will turn into panic and bitter regret.
Coach is your life and the exotic bazaar is the world, with your relatives, acquaintances and colleagues. If you invest, to your advantage, too much in your family or career, you will stay out. Life will pass by you, leaving you prey to your attachments you did not know when you were right. So enjoy every stop, but keep an eye on your life.