Damn good effort! Well done!
Good god, averaging over 450km/day for 30 days straight! I’d be chuffed if I averaged a tenth of that per day for a month straight.
45km per day is absolutely an achievable goal. Loads of people commute that far.
I encourage you to just hop on a bike and start. You don’t need to do it every day (or even both directions at first if your work has good facilities). Ride in one day, ride home the next etc until an hour on the bike is not too hard.
It’s cheap, good exercise and good for the planet.
Thanks for the words of encouragement! That’s exactly what I’ve done and recently just hit my first half century ride, but oh boy did I feel it! What a great feeling to be getting fitter though, I’m just sorry I didn’t do it sooner. Bikes are awesome.