I feel you. Having started a couple of companies, sold two, and watched the follow-on, it can be tough to see how others maintain what you created
A couple things helped me:
-Identity - Being able to separate what I did from who I am
-Control - Knowing there are things I control and things I don't, and aspiring to only feel responsible for the things I do control (aspiring...)
-At-bats and maturity - Selling a second company at 44 was a lot easier than selling the first at 23