I definitely had a similar experience. It took me 33 days after going full time as a founder to be profoundly regretful about a lot of dreadful advice I’d given out.
As a VC/Angel turned startup founder, I would like to apologize to all the founders I ever gave advice to prior to launching http://Copy.ai. Most of it was terrible advice. I hope you didn't listen to any of it. Feel free to reply below with the bad advice I gave you.