I had severe carpal tunnel syndrome from long-distance biking without gloves or handlebar padding, back in the days before we ever heard of CTS. It lasted 25 years before I finally got surgery.
Using a shovel definitely puts stress on the wrists. It sounds like you should see a doctor and get treatment for CTS.
Straight bars are a problem. Stand up and let your arms hang naturally. Now swingly them slowly back and forth and notice the natural angle of your wrists. They turn inward a bit. Now pretend you're holding onto your handlbar. To do that, you have to turn your wrists at an unnatural angle.
The solution to that, in my experience, is a handlebar that follows the natural angle of the wrist, which is about 60 to 80 degrees. Example: Nitto North Road
http://www.ecovelo.info/2009/11/23/n...tto-albatross/
Next, you need gloves. I recommend getting the thickest pair of gel gloves you can find. I have an old pair that are about 1/2" thick. I don't think anyone makes them that thick anymore.
Also, soft grips.
Finally, adjust the handlebar and seat so that your weight is evenly balanced or even shifted more to the rear. Use the most upright position that your style of riding will allow, to take as much weight as possible off your wrists.
Many people with CTS wear a splint at night to keep the wrist straight. Sleeping with bent wrists will aggravate CTS. But don't wear it during the day because you will lose muscle tone. I.e., don't become too dependent on it.
Really though you need to find out whether treatment is possible and if not, get the surgery. In the meantime, minimize everything that aggravates CTS, like using a hand can opener, any motion than involves gripping and twisting, and vibrating machines like a Weedwacker.