I'm in a similar situation vis a vis age and weight. My commuter is an older steel road frame with the usual attachments -- fenders, etc. I've ridden similar bikes for decades, and have not had a problem with typical road conditions, even occasional off-road shortcuts. Road bikes aren't as delicate as they look.
An issue for me is that I can't ride a bike with drop bars. My neck don't bend that way any more. OTOH there are plenty of riders at my age or older who have no problem with drops, so it's definitely an individual thing. On the other hand there's no law against putting upright bars on a road bike, as I've done. Why? I prefer a lighter, more responsive bike -- more fun to ride. The hybrids that I've ridden just seem sluggish and cumbersome.
At 22 miles round trip, I'd be thinking about a faster bike. Of course guys on hybrids and mountain bikes pass me on the path every day, as I'm no athlete. But this is only about what it takes to get me from A to B and have some fun while doing it.