Hi there ! It was nice of you to take the dragon to help it out. And WOW, the dragon really IS fat. He's roughly twice the size he should be. And I wonder if the previous owner knew the sex for sure, many owners don't. At any rate, just feed him insects twice a week, and not too many. The amount you've given will be fine, give or take a few, but load him up on good greens. I know if you're in the U.K. that your selection of good greens differs. Rocket [ arugala], dandelion, escarole, turnip , mustard are all good. Can you get a pic of his leg ? He may have gout. A medicine called allopurinol is used for treating it, but needs to be prescribed by a vet. Hopefully you can get his weight down, and sort everything else out. As large as he/she is, it may not have any interest whatsoever in breeding. A good half hour a day of running around for exercise, then an hour once he's used to it may help his weight, but watch that he doesn't fall from any height, it would make his leg worse. I wish you the best with your new critters !