“Everything would be cool if I only I had (done) X”.
No. It wouldn’t.
Because right now you’re the kind of person who’s concerned with the opportunities he had 10 minutes ago or 10 days ago or 10 years ago, instead of the ones that are right in front of his face right now.
And guess what? Back at time T, when you now wish you had done thing X, you were talking about how awesome it would have been if you had only done thing Y at time S (or thing X-1 at time T-1, take your pick).
And at this rate, with that mindset, 10 days, 10 months and 10 years from now, you’ll be talking about how awesome now was.
It’s not the time. It’s not the chances. It’s not even you (you’re not broken, as much as you might like to be; you’re not a tragic hero, you’re happy and overfed and free and you’re going to live a long time and die in peace). It’s the Monday morning quarterbacking.
Stop trying to do what you could with what you had. Stop trying to win yesterday’s game.
Do what you can right now. Use what you have right now.