Fellow founder here. It's tought and tbh, I often don't do what I preach. First and foremost: There will be good times, there will be bad times. The feeling of getting "in the black" for the first time is nice. Getting back into the red for the first time is far far worse. But: You will get through it. Maybe not your company,but you will. One of my clients is a self-made multi (as in more than 100) millions. How she did it? She failed three times before her current company went widely successful. She only could do so, because she did not give her last, didn't kill off her sanity by working 80h for months when things got tough.
But to become more practical: Create a protocol. Follow protocol.
Sounds strange? It isn't. You will by now know these situations when you are in a hurry and need to do things for the first time and we often think of them as "ah,I can fix it later, we are small, I will remember to do it this way,etc..." Then you have these crunch times when everything is coming at you at once. Trying to remember then how you did something 6 month ago takes time. Far more time than writing it up once. It helps your staff as well - because you will be handling things the same for everyone. Nothing is worse for company culture than staff that doesn't know how to do things if person X (you?) is not there because things get done differently every damn time. And, as additional benefits: You can then delegate things much easier and without as much hazzle. (Or let someone pick things up after you if you get hit by a bus or break both legs)