OP, we have VERY similar histories. At 46, I compete against myself as I have discovered group rides are not for me, and the commute + Strava gives me a great workout. Formerly around 240 lbs in my early 40's (and was on Diovan).

In fact, I have a hard time slowing down (not that I am fast) while on my commute. I gauge my race by how hard I am breathing.