I also have had bike-related injuries that have really impacted my ability to ride longer than 45-60 minutes. Thankfully I've found other activities (weight lifting/metabolic conditioning/cross-training) that I like just as much as riding, but I MISS being able to just go out for a nice 40-50 mile ride to explore the countryside. I was in denial for some time in thinking that the only real impact was to mountain biking, but that has been proved wrong. At least I CAN still ride short distances - and the almost daily rain for the last month has meant that I've not been able to ride more than once a week (if that) as it seems to only rain when I've a "riding window".

It is sad that those few people I've ridden with in the past no longer asks me to ride since I've had to turn them down so many times due to these physical issues.