Sorry you are here. I wanted to respond to you because your sitch sound simmilar to what happened to me. My W was overweight also for 6-7 years after 2nd s was born. Around 4 years ago she had GB surgery and lost alot. I will say after losing the weight she was looking very hot again and started to get alot of attention from other men. I think that was the begining of the end for the marriage. Pretty much heard all the same things your W said to you. Dont be surprised, if at some point being in MLC, she will blame YOU for the fact she was overweight. Something to the effect of "You never loved me and made me miserable so I ate to ease the pain". But as you probably already know, YOU were to blame for everything in her eyes.
Might want to check the courthouse also to see if she really did file. You want to make sure you legally protect yourself at this point.
ME:47 WAW:45 SON:19 SON:12 M:21 yrs T: 22 yrs BOMB: 3/26/10 EA/PA apr-may 2010 Current: no OM (I think) moved out sept 2010 D filed D w/b final 4/6/2011