You are right, a "regular" kid isn't going to compete with one where the family makes everything about junior's tennis. This is why you need to set realistic goals. No matter how good you are there are always people that can give you a 0 & 0 beatdown. And then more that can beat those people 0 & 0 and so on.
Yea, I've been down that rout personally years ago. Entered some tournament and got smoked by some guy that could angle his one handed backhand like nobody I'd ever seen before. He won the tourney btw. I've played a lot of hockey and tennis and always thought that tennis was the harder sport(unless you can't skate). With my kid he has never experienced that and I am kind of protecting him from a beat down until I think he can handle it as just a learning experience.