in fact, they shaped my sense of self and character, instilling in me focus, drive, and confidence
Give an example otherwise it is too general.
It's for exactly this reason that I chose to pay forward this tremendous contribution to my life by coaching, refereeing, and officiating basketball for the same city that raised me.
This is grammatically incorrect. I can only vaguely understand that you are repaying the benefit that basketball has given you by coaching, refereeing, and officiating basketball games.
I like the second paragraph but you should add a conclusion. You may write about what effect refereeing has had on you to finish off but its up to you.