Kevo,
Yes a one-man shop can make it. I've been doing it for nearly two years. But, there is a catch; I have part-time help. More and more I'm going with 5-day weeks, and even closing my doors for a day's vacation.
As others mentioned, you need to be aware of your own limits on how much stress you can take. Screen the jobs, at least when you are busy. When you are slow you can afford to do the less desirable jobs.
My experience has been that customers feel safer dealing directly with the owner/technician. It's a real handful to do most everything yourself but very rewarding! After all, we didn't choose this occupation to just loaf around, but to meet the challenges of the automotive repair world!
So I give you my best wishes and if I can help you out anytime, let me know. Looks like we are geographically not too far apart.
Regards,
Jon