I ran a consulting company for over three years. I ended up divesting myself of that business earlier this year. We were ranked as one of the 250 fastest growing companies in our sector by an industry analyst two years in a row (2012 and 2013). I was working hours even more extreme than you for the first year.
We did great work and grew very quickly so it was hard to keep up with the growth. We made mistakes and we alienated some customers as we grew. Yet, I knew early on that I would need to hire people to help me grow. I tried to document as much as I could about our systems, processes and procedures. That way I didn't have to spend as much time training replacements.
The trick is in finding good people to work for you. If you are hiring people and they make your life more difficult (clients are upset, etc...) then you need to change your hiring strategy.
Your company has a unique way of doing things. Judging from your description, it's a very stressful and high demand environment. If you are going to hire someone then you need to hire someone who is a good fit for that kind of environment. Try and find someone who has been an entrepreneur in the past and don't be afraid of making mistakes that alienate some customers. If you didn't make mistakes you wouldn't be human. Just try to ensure those mistakes don't put you out of business.
My advice is as follows:
* Take 10-20% of your day and document what your doing. Draw diagrams if you need to, but make sure you understand the work to be performed.
* Hire People based on their passion not their skills, and train them.
* Work hard to ensure you create a relaxed work environment for the people who work for you. It takes much more time and money to retrain new people than to retain people.
* Take responsibilities for the failures of your people, offer training not blame to keep them working hard.
* Plan to take a trip after new people are in place to do the work. Think about where you want to go and imagine yourself relaxing.
* See a doctor about the stress and apathy, this kind of stress takes a toll on a person, it might be necessary to get on something like blood pressure meds to keep you healthy.