Giving advice- I love this.
Well the fact is from the little i know you have a ten out of ten, and you should be advising us, but turning puce, or purple as you put it is not good.
Yes, it's growing pains, and also trying to do all that networking and show attending.
As regards the business model, if you have two vans (i assume van three is basically you) pretty much full with your own work that has to be healthy.The further away stuff, sub away. This is pretty much how you do it already, so carry on.
I like the idea that you are getting better and better kit, try and relax about how much money you are spending.In your shoes i would note that Charlie, after three generations of high end and high volume w'cleaning is still stressed.It's never going to go away.I would want to at least look at copying the spec of his vans and find out why scalability has worked so well for him.