Sex related (don't know where else I can ask)

Please bear with me for talking about such personal stuff, but I really don't have anywhere else that I can think of that I can possibly get some input from others that may be experiencing a similar problem.
I married 7 years ago and during this time my weight ranged from a low of 270 to a high of 310. As of this morning, I weighed in at 239.
Some might not consider my problem much of a problem, but it really is.
After losing the weight my wife says that she notices the size of my penis is bigger. Enough bigger that sex hurts. Prior to weight loss we were very compatible sexually. Though now I have more stamina, energy, and due to working out a higher libido, my wife is less interested in sex. When we do have sex she says that it is either uncomfortable or "just not the same".
Am I on an island here or does anyone either relate or have any suggestions?