Two can play the game. Teach the kids to say "It's a Cult" a lot. Teach them to say "Jehovah doesn't like false prophets."
Seriously, it sounds like your wife has completely drank the Koolaid. She has completely lost respect for you. No wife who respects her husband would do this. Trust me. I was in this situation when my elder husband stopped attending meeting and going in service. My thoughts were "if he's not going to be in the truth then why am I staying in this marriage." If only I knew then what I know now, we'ld probably still be married. With JW's, it's all about "serving Jehovah together as a family." Even romantic love is based upon both of you staying "in."
You have my deepest sympathy but the kids have to come first. She is not teaching them to have respect for you. You need to demand that she and the children show respect for you. If she throws up the "you have to earn our respect and you aren't going to meetings so you don't deserve it" well then, I leave it in your capable hands to find the correct words to set her straight.
Be exemplary. Don't give her any ammunition to use against you. No violence, no threats. Keep things calm and civil.
Get yourself up and out of this depression. See a doctor, start working out again and get yourself well. Your children need you to help them escape this cult. Perhaps, one day, you wife will follow.
Best of luck to you. Keep us posted.