First of all, I don't think most of us will reach a stage where you are satisfied with everything in your life. There will always be regrets and more.
Secondly, how do you find happiness or let's say peace? I didn't think too much about it but i believe it is something spiritual. You have to build yourself an ethical system or embrace it from a religion that you like. Follow it and try to be a good human considering there is no absolute good or absolute bad for humans. We are trying to fight our demons, in the middle ground. If you can live according to your believes an ethics i think you will be okay.
I believe everyone lives with anxiety, boredom and depression or lived with it at some part of their life. We will live in stressful times. I am also rn not in a good state because of some reasons i don't want to mention. But if i can peak somewhere or try to get better everyday i believe eventually it will all be good.
Finally I don't think there will ever be ultimate peace or relaxation in this world. You either work hard everyday or don't give a shit and live a miserable life. Most of us are kind of in between