Most of the guys I have seen come in for consultations because their wife unexpectedly filed are SAHDs, in school, unemployed or just make less than their wives. To a man they all say that their wife supports or even asked for this arrangement, or it was never a problem, that cant be the issue etc. You can make your own conclusions about the reasons why, but it seems to me that despite what they say, many women don't want to be married to a man who is not the breadwinner. Usually, it comes out that the wife is already involved with or has her sights set on a boss or some other perceived high-flyer.
For you, being a SAHD makes this pretty scary as you may feel dependent on her, but it also gives you all the same rights and advantages enjoyed by SAHMs in terms of spousal support and advantageous custody. Dont sign anything until you see at least a few attorneys, especially looking for any that specialize in fathers' rights. Do this immediately, and share nothing of this with her. If she if filing first, you are on the defensive starting now.
Start keeping a hidden notebook documenting anything you can showing that you are not violent, not abusive, and the primary caregiver to the kids. Your wife's attorney will be telling her that when push comes to shove, she will have to make a play about her doing this to protect herself and the kids, so expect this will be coming. You dont believe this now, but it always happens. She will demonize you to anyone who will listen, the more guilty she feels, the more its your fault. She will be saving emails, texts, and if you are in a one-party listening state, she may record you too. Dont give her any ammunition. SHe will make things up, lie, and embellish. You must create a documented counter-story.
ALso, giving her good or easy divorce terms will only make her more likely to want a divorce. Another common theme for guys I see in your position is they try to placate their wives/are afraid of making them angry/wont stand up to her affair/are afraid of driving them away. I often think such displays of subservience to the wife are what is making her want a divorce in the first place! Worry about yourself and your kids, dont be afraid of her or try to do anything to make this easier for her. She is causing pain and destruction to you and your kids, she must feel consequences.
All of this requires a huge change in mindset about who your wife is. Unfortunately, from a legal standpoint, once those papers are filed you are adversaries. I know you cant think of her that way yet, but she can.
