Deb is right. It doesn't take long to get bike fit. And being a beginner again is really fun, so look forward to each ride for how great it makes you feel and enjoy the experience. Getting more fit and adding the miles is a great process, and one you don't get to experience too often, so enjoy yourself.

You are not the worse. You think 3 1/2 miles is really bad; you are wrong. Well once, years ago, I witnessed two couples, age 50s-60s, park at the state park, get out their bikes, tinkered with their bikes, finally got on the bikes, pedaled at most 1/4 mile and one of the females collapsed.