I guess I wonder if my biggest priority is to be home with the kids, do I just go, detach, and get the most time with my kids as possible? Or do I go ahead and get out now out of fear as to how bad it might get?
I choose to stay with my AH for financial reasons (amongst many other reasons). I have a much nicer lifestyle with him than I would without him. Its a big thing, in my opinion (financial security) and can play heavy on your mind, as it sounds to be doing with you. When our DD's were younger, I didn't want to be a single mum struggling to survive, so I chose to stay/return many times. Many on SR are happy they have left, however humble life they lead now, due to the peace and serenity they have in their lives, no longer living with the alcoholic behaviors. I suppose it depends what you can put up with and live with. It also depends if there is any abuse and how much of your current lifestyle is effecting the kids too.
Just as a side note: wives stay with extremely wealthy husbands who have affair after affair etc because of the lifestyle they are provided with by staying in a faithless marriage. Incidentally these wife's would possibly be fairly wealthy and mentally healthier in their own right if they ever left and divorced their husbands, but they don't, again possibly down to their own self esteem being bashed (I am guessing).
I am not suggesting that your husband is wealthy (at all) but there is no shame in staying, if your not ready to leave, then your not ready - simple as! You will know when you are ready, keep planning, squirrel away some money and when you have finally had enough and the negatives outweigh the positives then you will go and feel happy about your decision.
By the way, I am currently living in ambivalence with my AH, not sure if I want to stay, not sure if I want to leave - trapped in the middle. Ambivalence is not a healthy way to live because you really need to put 100% into whatever you do. I too struggle with the 'not knowing if your coming or going'. Sometimes my husband is nice/horrible he says something positive/negative, he disagrees/agrees, I pictured the seven dwarfs the other day and that made me laugh (in particular sleepy, happy and grumpy). Its not an easy way to live at all, so I completely understand where you are coming from.