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.