Feeling a little overwhelmed, first time on this side of PH - Any advice?

Just for perspective, my first computer was a Commodore 64 with a casette player....I used to spend hours making text games with dumb narratives...Never got into programming but I was hooked on the infinite possibilities. Spent my whole professional life building websites and web Apps in my own company and for others as an employe, always on the "Product" side, never on the code. I worked with many great developers and I always thught..."Should have learned to code.....The things I could do if I had just put the time to learn"

FF to late 2025 and in a blink of an eye and after paying for $100 sub, I could finaly code....well, you know what I mean...

Now, 35k lines of code, 1300 unit tests and 3 different versions - From a MVP in Python and Electron to a full blown C# over WinUI , Im finaly at the Start line, with a Launch day scheduled... I should be feeling great about this but....

Im stressed, not sure wht to expect and a little bit cluless on what to expect and how to handle it - Any word of advise will be trully appreciated