The bigger issue is that it appears you have just gotten yourself another job, rather than a real business. My definition of a business is a "profitable, commercial enterprise that works without you," and obviously, you are not at that level--yet.
Systemization will help . . . as well as finding some way to segment your operations geographically. Either that, or finding a way to centralize your operations and have your customers/players come to you.
More important, remember that coaching is very people-oriented and personality-driven. You are correct in worrying about "hiring" other coaches which makes the process by which you would hire and train people into your "system" one of the most important components of your business. You want them to have a very specific personality profile--one similar to yours. I use the DISC profile in my own business; it's an effective and inexpensive way to get a base profile of prospective hires.
Finding a way to make your coaching business work can be done. Trust me, if I could do it with business coaching, you can do it with football coaching--because there are a lot of similarities between the two professions.
All the best.
Brad Sugars is the founder and chairman of ActionCOACH. As an entrepreneur, author and business coach, he has owned and operated more than two dozen companies including his main company, ActionCOACH, which has more than 1,000 offices in 34 countries.