Just to pick a couple random points and expand on them...
As a rough rule of thumb, they say it takes 10,000 hours of hard work at something to get truly good at it, i.e., good enough to do it professionally. In other words, most people are only going to get truly good at 1 or 2 or 3 things in their lifetime. As for every other interest or experience they have in life, they're going to be dilettantes and amateurs at those things: They're going to suck at it or bumble through it or fail miserably, or whatever.
1) When it comes to the 1 or 2 or 3 things that you get truly good at (typically, the things you choose for a career), focus on choosing something that's a good fit for you: It fits your mission in life, your background, your personality type, or whatever. The better the fit, the easier it is to master things.
2) As for all the other experiences in life, realize that you're never going to be very good at them. You just don't have the time to get truly good at lots of things. But everyone else is in the same boat as well. So focus on having fun with those things, pick a wide variety of new experiences to sample, and be generous toward those who share those experiences with you (since you're all in the same position). Don't think in terms of win or lose, fail or succeed. You're a dilettante at those things; just have fun with them and try to enjoy the experience with the rest of the dilettantes sharing the moment with you. (Or if the outcome is really important to you, then pay a professional to handle that thing for you; IOW, don't kill yourself trying to second-guess the pros.)
Also, the following is good stuff for overall attitude toward life:
Remember that you can write the "narrative" of your own life: As for looking backward, celebrate past personal achievements and keep them in front of you; make a "trophy case" of mementos to remind yourself of where you come from and what you've done so far. As for looking forward, be deliberate in your choice of future priorities in life; write up a personal mission statement of where you're heading and what steps you're actually taking to get there, and then update it regularly.
IOW, don't free-float through life. Devise some Fi tools to anchor yourself and create a "personal narrative" to help identify who you are and what you want to achieve. Keep your goals in front of you.