I, too, want to congratulate you on the weight loss ... that is REALLY a great accomplishment. And, great news that you're looking into cycling as a form of exercise and fitness ... I expect many on this forum consider cycling to be not just physical exercise but a stress reliever and sort of a mental and spiritual escape.
A few, in no particular order thoughts I had:
- First, don't stress over what others are doing ... in terms of speed or distance or what they're wearing or how much their bike costs. Cycling is meant to be a fun activity and we shouldn't make it stressful by comparing ourselves to others in a way that makes us discouraged (vs. using it as motivation to improve). There will always be someone riding faster and longer etc etc ... just enjoy whatever place you're at and any personal goals you may have set for yourself.
- Increase your riding according to your own pace and health ... find that sweet spot where you're challenging yourself but still having fun and not risking your health.
- Stay active ... whether riding regularly or other exercise ... especially as we age, we atrophy/fall out of shape very quickly. It's a bummer to feel like we're starting all over again because we keep taking breaks from our fitness routine. I say this as someone who is NOT disciplined to exercise doing things I don't enjoy. I ride regularly because I really love it. So, find a regimen that is enjoyable to you so you'll be motivated to stay with it.
- In the spirit of giving advice that I don't follow ... try getting into the habit of doing stretching exercises and even light weight training (cycling is great exercise but the benefits are more lower body and cardio)
- As others mentioned, and especially if you increase your mileage ... a bike fit and a bike with a more comfortable (non-racing geometry) will help in making longer times in the saddle more comfortable. Related to that ... get a comfortable saddle and don't overinflate your tires (that can make the ride feel more harsh).
Keep us posted on your progress ... always love to hear how riders are doing in the sport we all love!