Glad you're back. I had colon cancer in 2003 and I started riding in 2004. The cancer came back in my liver in 2005, and cycling probably saved my life. I got away from it in about 2012 and recently came back. I think the key is not constantly pushing for more distance and more speed, but to set reasonable modest goals. Pushing to go farther and faster results in burnout - at our age, reasonable distances are the key. Just don't stop.