First up thanks for sharing 123cups. It is wonderful you think of PRE as somewhere you can seek help/advice - and you are right
Just thought it was interesting you made the comment "and I'm not sure if I'll even achieve a fraction of what everyone once expected from me." We cannot control what other people think of us or what they expect from us. That is their issue to deal with. What is more important for you is how you think of yourself and what expectations you want to put on yourself. As TBR mentioned above go and seek advice from you GP and get a referral to someone who you can talk to professionally and work these out in your own mind. From your comments it is obvious that you are in a world of self doubt and you need help to clear the fog.
When self doubt has crept in on my world I found helping others to be a way back. Find a not for profit organization somewhere near you and volunteer your time. Might only be an hour a week but these organizations will need the help and you can get some personal satisfaction. You never know what you are seeking may materialize while volunteering.
Just a couple of thoughts. I wish you well on whatever your future path may be.
Have gone through patches of this in my life. And on the theme of volunteering. Sports coaching kids I have found an enormous pick-me-up.
Prior to having my own kids, I coached a lot of athletics to tweens, teens and young adults (some from their tween years right through until they were young adults). And have recently got into coaching 5-6YOs soccer. Never been paid, always a volunteer coach.
There is just something about seeing their happy faces, feeling their enthusiastic energy and seeing their confidence, abilities, tenacity and pure joy grow exponentially, that is infectious. Plus witnessing and feeling the bond and camaraderie they develop with their teammates (and coach) is a beautiful thing. And you get a buzz out of knowing you have facilitated this.
Training days and match/competition days become some of the highlights of my week and I look forward to catching up with them (and their parents).