Some thoughts: Reduce the number of possible chancy things by cutting your milage down to say 3000. Try to eliminate objective dangers - like don't ride on wet roads, during or after a strong windstorm, etc. That'll cut the mileage down right there. A 60 mile day is plenty. Just ride it harder. A 100 mile week is plenty - that would be one 60 and two 20s. I also run, walk, hike, backpack, and go to the gym, which all improves my riding and, except for the gym, gets me outside. Outside in the mountains, if you have any, is much more refreshing than riding. We'll drive for up to 2 hours each way for a hike.

I try to be a very safe rider. I don't ride in bad visibility or after dark, I run bright blinking lights fore and aft, wear bright jerseys, never any green or blue. I've had a few accidents but nothing that kept me off the bike for more than 15'. It helped that I know how to fall - keep my hands on the bars as long as possible. Maybe all the gym time helped, too. It probably helped that I've done a lot of my riding in group rides. With the right company, group rides are safer than solo.