A nice story-- I built my own SaaS (in the middle of year seven now). A similar story... I even read Rob Walling's book and even went to a local Microconf.
The numbers grew slowly and have pretty much plateaued. It's my dream job, and I can't imagine going back to work for anyone else.
I do have an existential dread though--- mainly, "what if my revenue goes to zero?" and I constantly think about how to improve the service or build another service on the side.
Though, it's still better than the dread that comes with being employed and potentially laid off.