My suggestion would be to find a lbs and do a proper bike fitting. I'm sure there are people here that can get a view of you on your bike and likely get you pretty close. But I feel that a legitimate bike shop is going to be professional in their approach, and Im sure they will make you as comfortable as possible during the fitting. They will have the knowledge and know how to get your body in the right position on the bike. Or atleast as close as you can get it. I certainly understand your feelings about the extra pounds and the modesty. But I commend you for doing something about it. Dont let fear keep you from riding comfortably.