Mark, let me throw in a couple suggestions. First, living alone, you might try developing an informal support group. You could reach out to a few parishoners who either bike themselves, or who generally have a fair amount of free time and a pickup. Just ask, "If I run into trouble on a ride this week, could I call you to pick me up and haul me back home? I'll pay for gas and a hamburger!"

Second, It'd be a good idea to address your balance issues. A few sessions with a physical therapist should give you a list of exercises to develop and/or maintain balance. Since falls are a major risk for elderly people (not that you're there yet), insurance might cover those sessions. Even if insurance won't cover them, a few hundred bucks out of pocket can save big on co-pays in the future.

Neither of which helps with deer running into you. That sucks.