"gman421"......Is this your first diesel pusher and/or Class A motor home? If so, you might consider this. Often, new owners try to steer these coaches like their car. Stay between the lines and steer directly in front of them. A motor home is different. On your next trip, try looking farther down the road. Don't look directly in front of the motor home. Pick a spot a hundred yards or so ahead and steer for that point. You'll find that you will do less wandering.
Second, your coach has a tilt wheel. Tilt it all the way up and see how it steers. It becomes difficult and awkward. Tilt the wheel down as far as comfortable and you'll do less steering.
Lastly, you should have adjustable armrests. Position them and your seat so you can rest your arm on the armrest and still grip the wheel. It will help you to relax. Make sure when you adjust the armrest it's not up to high forcing your shoulders up, or they'll become painful by the end of the day.
If this doesn't improve your wandering, then check into what others have suggested.