Been photographing small events gratis for love of the game. How do you make the transition to semi-pro work?

Preface: I'm not looking for advice on getting paid for past work, admonishments that I should have gotten a contract, being told I'm stupid, etc. I knew what I was getting into. I'm curious about how to move forward from here.

I've been a hobbyist photographer for 20 years, mostly landscapes and flowers and such. Recently, I've been going to a lot of corporate events (company parties, book launches, Make-A-Wish fulfillments, etc) because my wife has been making friends in the corporate world. Rather than deal with socializing and networking, I've been opting to bring my camera and take pictures for my own enjoyment, which I then share with the relevant parties for social media use.

Unfortunately, it turns out I'm pretty good and I think I've somehow slowly backdoored myself into being a semi-professional official event photographer.

Most recently: My wife's personal trainer collaborated on a health and wellness book, and asked if I would be willing to take photos for the launch party. I got a list of coverage wants, snapped about 550 raws, and delivered about a hundred 6mp jpgs (cropped & color graded) within 48 hours. The event took about 3 hours, winnowing and light editing took about 6 hours on a lazy Saturday.

On the one hand, I genuinely enjoy doing this as a hobby and I'm concerned that starting to do contracts and fee structures will suck all the joy out of it and create a different kind of performance pressure. I've never wanted to be a professional photographer and I've intentionally avoided it to this point. On the other hand, I'm starting to realize I could actually make some money off this and should probably take some bare-minimum steps to protect my intellectual property.

I'm curious to hear from anyone who made this transition, especially those who didn't really seek it out in the first place. Using the above example as a benchmark, how much might I realistically be able to charge for this (especially given that most of it is friends, family, and friends-of-family)?