zandoval 

I had to get over it - Having been in younger years a competitive cyclist I am often appalled at how slow and how often I have to get into my 34T bail out gear - At 60 I have lost so much that if I take a long ride 50 miles plus I am toast for a week or more - I now feel better about my riding if I can ride a 30 mile easy one with some hills and only need one or two days recovery - I would say change your ride and work on your endurance rather than speed...

To loose weight make it simple - At your height and weight log all your food and add up at the end of the day - Look for about 1600 to 1800 calories to include 90 grams of protein - That will knock off a couple pounds a month...

Also keep in mind that at 280# you have exceeded the max weight that your knees can mechanically tolerate without injury - Keep cycling at the forefront to spare them - Running and Jogging especially down hill will cause knee damage...

I have tried a few group rides and always felt like I was holding them up - I am still hoping to find someone to ride with but most of us Geezers ride solo...