I have the same problem to some degree and I believe we have all been there! My biggest problem is worry! What if's drive me crazy! What if the work slows down, the compressor dies, the lift takes a crap, my computer dies...! Several years ago I quit (all recorded here in the forum). Left town in search of greener pastures. And wound up right back here! It is all a learning process. No one can tell you exactly how to run your business. And when it's all done at the end of the day the only one responsible for you is you.
My first move was to stop worrying! Second I began weeding out the cheap customers. Then I slimmed down the overhead. if it dont make me money I get rid of it. And lastly I work alone and schedule accordingly. It's still tough but it is MY tough! I got my leg broke last November and was sure I was gonna loose it all. My son stepped in and took care of biz till I got back to the shop. and guess what! It was all still here! I took a vacation in August. Didn't have a thing on the schedule for the following week when I got back! Wanna take another guess..it was all still here when I got back and the phone rang of the hook for a solid week!
And for what it's worth I pray! And my GOD answers prayers! Am I where I want to be? Not by a loooong ways! But I dont wake up in the morning and get sick thinking about the business! There is a reason you started your own business, rediscover that reason, make a plan and stick to it. Make adjustments when you have to, but stick to it!