Congrats on making it, Matt.
I quit my job to focus on the side hustle full-time back at the start of 2020 (back when we all thought it was going to be like any other year).
The hardest and most stressful part by far was renegotiating boundaries with my wife. Being physically around one another all the time, and having no set hours is a recipe for relationship woes. Having our first kid during the lockdowns (we're in Melbourne, AU) didn't help either.
Almost 3 years later, life is great, but for a time there it was the worst it had ever been. Make sure to take the time to negotiate boundaries, as all problems become work problems when you run your own business.