I found the easiest thing to do and it actually felt right on for the times, I simply said to myself that (x)W was dead. Which in her own right, she was. As with your H, no longer the person he once was. Treat him as such and you will feel better about things. Trust me.
As far his self asteem, yeah, (x)W was always very self conscious of herself. She was in fact always a plus size woman, but proportionate and I never had a qualm with it (aside from certain wore drobe choices and hair does, that were well, just tacky).
As the M fell apart, she lost weight dramatically. I think that's what also hepled fueled the OM, they knew each other for years so perhaps she returned to a figure he was obsessed with in high school or something, who knows. Then her conscience started getting the best of her during the D and after and she started to fill back in to her usual frame and OM didn't like it. Heh, guess that also helped remind her of who loved her no matter what.
Me 35/XW 33 S13 & S12 M: 10/17/98 OM & S: 07/08 D final 06/09/09 12/03/09 - 06/13/10 "Piercing" 06/13/10: Engaged to Re-marry 10/17/10 06/25/10: Expecting baby #3 2/14/11