I hope im not just repeating what has been said earlier in the thread. I have read page one and the last two pages and just want to echo what everyone else is saying to you Stars. My ex H was similar to yours in that me and my DC's used to spend every weekend walking on eggshells waiting for him to 'start' He was only home at weekends thank god but they were hell as was every high day and holiday thanks to him.
He started off like your DH too, just snidey comments turning into actual full on nasty evil treatment. And that was just for starters. I would hazard a guess that if you answered back or started to 'stick up for yourself' in any way it would almost certainly turn physical - my Ex H did when he found he couldnt control me anymore.
Stars if you are scared take comfort that there are countless women who have been through what you are going through right now - it took me years to get out and debt or no debt you should be making your plans now. If you dont have the courage yet can i recommend a book i read which will help you to identify your DH's behaviour almost certainly. Its called ' The Charm Syndrome' and its by Sandra Horley and endorsed by womens aid - i found it to be a valuable tool in helping me to see that i would not be able to change my ex's behaviour towards me.
You and your DC's deserve more, my girls will never ever forget what my ex did to us and although it was 6 years ago now they do carry the scars of living in a household where domestic violence was pretty much part of their lives every single weekend. They rememeber when the police came, they remember when he hit me so hard i lost my hearing for a month and they remember when we walked away to the shittiest tinest little flat that some kind friend had lent us for a few months. Leaving behind their private school, 5 bedroom house and seemingly easy middle class lifestyle was a breeze for us all - compared to the life that we had been subjected to. My youngest DC is currently undergoing councilling for her issues left over from those days and she has so many problems because of them it will take a long time for us to all come out the other side.
Luckily we have a wonderful man in our lives now and my girls realise that this is not how men treat their partners/wives - they have a new baby brother who is six weeks old and i never ever thought after what was done to me that i would ever trust another man or be happy again. I am telling you this so that you know that it isnt the end if you walk away, you and your DC's deserve more than this - its only when you walk away that you will realise just how badly he is treating you. I wish i could say that your relationship could sustain but it sounds to me like he is treating you like this exactly because he is a bully and he is getting away with it. No amount of depression, cheating or any other excuse that is made for his behaviour can be used to treat another human being the way he is treating you.
My ex H used to say i was a terrible housewife, fat and ugly (im fat but not ugly!) he would tell the girls terrible untruths about me and accuse me of cheating when i hardly went out. You know in your heart of hearts that the way he is treating you is wrong and i think you probably know that it is time to get out before it gets worse.
Speak to womens aid, nothing has to be done right now - find out what your options are and if you can possibly get hold of it get that book - it was a total eye opener for me. I didnt realise that abusers come in all shapes and forms and that my DH who seemed so utterly charming and a pillar of the community was one too - he blamed me for his behaviour just like your DH does to you and its part of the control and abuse.
Sorry if this post is long and rambling but i just wanted you to know that you are not alone and this happens sadly to alot of women - you have children though and they deserve a happy mummy, i hope that you are able to sort this out and find some strength from somewhere. Good luck Stars ...