I'm sorry that you are going through this. Please do get therapy for yourself as soon as possible. It's obvious that your wife has something going on and needs some major help to, but it is unlikely that you will be able to get her into therapy based on what you have said here. I would highly suggest that you consider therapy for your daughter too. It sounds like her mom has been very hard on her and this could be causing her some distress that you just aren't seeing. I think for your son, maybe see if the school can escalate the issue? Then you aren't the bad guy?

Also -- if you decide to leave, try to take the dog too. Again -- I'm so sorry you are going through this.