Every project has a price at which you know it is worthwhile. Sometimes it feels funny to estimate high...even 3-4x your normal rate. But trust yourself. Understand the additional costs in your time or energy. Likewise, some projects or clients are worth working below your normal rate.
You have a fantastic problem on your hands. The demand is exceeding the supply.
I would suggest raising your prices for all new clients. You might also consider bringing on subcontractors to handle the smaller jobs for you.
We've done a lot of work on our house over the last few years, and I've observed how different contractors deal with scheduling issues:
1. Some won't return a call at all.
2. Some will call you back to say that they're in the middle of a project, and are too busy to take your business.
3. Some will happily schedule you in for a date in the distant future (like, three months from now).
I'm unlikely to bother calling the first two again for work, but the third makes me think, "Man, this guy is so busy that he's booked until March? He must be good."