I agree with others, there is no one thing that is going to change your life. You get there via experience. Experiencing the consequences at 30 of something may feel profound despite the fact your parents told you the same thing 100 times as a youth.

My advice is this: Introspection is a super power. The more you take the time to step back and reevaluate all of your actions/assumptions in life, the more you will be able to make meaningful change towards the life you want from NOW.

Also, find purpose outside of your career, find a hobby or cause and find fulfillment there. Corollary, if you are going to have regrets, regret doing something, don't regret not doing it.