The feeling never really goes away. For me at least.
I just accidentally raised $1,931 yesterday for Tensorfork Labs, a non-profit I started ... also yesterday. https://twitter.com/theshawwn/status/1431462744906141696
I was blown away that everyone suddenly offered so much support. We have people filling out notion docs (http://wiki.tensorfork.com/) and an active Google Chat chatroom with 12 interesting people in it. And to top it all off, Nat Friedman (Github CEO) DM'ed me last night and I'll be talking to him in approximately three hours.
You'd think I'd feel thrilled and like I'm extremely effective. I am thrilled, but all I feel is that I haven't done as much as I could. Talking and walking are two different things, and now that we've talked, it's time to walk the walk. But the truth is, I felt guilty sleeping most of today while everyone else has been talking excitedly. I felt that if I pushed myself a little harder, I could've been more effective, or more diligent, or lived up to my responsibilities more.
But that path leads to burnout. Good work is a marathon, and things take time. (Unfortunately it sometimes seems ~impossible to internalize that, and the temptation to sprint is always there.)
If you're looking for a mental hack to make the feeling go away, the only thing that helps me is to remind myself that even small deltas have value. My personal goal is to make imagenet2012 accessible to every programmer. It's a small, obscure itch that I am scratching for myself. But it's mine, and I can fix it, which is good enough.
So just do what you can, where you can, and be authentic. No one can know how things will play out. Doing your best is all you can ask of yourself.