I just participated in the Landmark Forum (https://www.landmarkworldwide.com/) which is designed to do (among other things) just this, over a three day intensive class. It's about redefining the way you look at the past, present, and future and establishing more positive views. As someone who has been studying mindfulness (and, where it's related, Buddhism) for the past few years, it was a very welcome experience, and it's already impacted my life and relationships in a number of positive ways.

Google it for yourself...as with anything "woo", there's both positive and negative comments out there. But for me, it was the right thing at the right time, and it's inspired me to take action in very meaningful ways.