Gosh Deb- I've been thinking about you and wanting to post but I just have a few minutes.
I just read about a couple overcoming an A in my Ladies Home Journal (Can this marriage be saved article). Their counselor recommended that they set aside 20 minutes a day for the W to cry and carry on about her H's A. He was to listen and hug and support her during that time. But once the 20 minutes were up, that was it on that topic.
Although I think it is good that your H is sharing, I think he is being unfair with how much he is unloading about OW on you. And as much fun as it can be hearing bad stuff about her, I don't think it is helping you, him or the two of you. What if you tried the 20 minute thing and told him that you think he needs more help than you can give him? Counselor, clergy, good guy friend as an alternative?
I would also set a boundary regarding H's reference to your weight. If you feel that you need to work on it and are actively trying then that should be off limits unless he wants to help and be supportive.
Regarding the sex performance- I looked up "delayed ejaculation" on WebMD because my H tends to take longer since the A. And outside of abnormal health conditions, a affair is definitely a contributor. The article also said that few men can take care of solving that one without counseling. Quite honestly, they should be happy that we are willing to have sex with them so soon after all this crap! We should be the ones having issues.
Anyway, not to be blunt, I just wanted to get you something today!