birdybear I am so sorry you find yourself in this difficult situation.
If his treatment ever turns violent towards you or the children, please protect yourself and your children. He sounds as if he is being totally horrible and this is not normal behaviour IMHO.
I know there are two sides to a story and we are reading your side of the story. What would your DH say?
Just be aware that he may also be unhappy. If you manage to really uncover what is causing these issues, he may reveal hurts from the past etc which could be poisoning the current family life.
I really agree with all who say you need some relationship guidance counselling. He needs to see you as an equal in this marriage and family, he needs to share his time and money with you and to take time with his kids, and not just the fun stuff. He needs to act respectfully to you and his children. Maybe a third party can help him see this in a way you would find harder to convey.
It sounds like he too is unhappy so if he is maybe that can be a starting point, that you both want to make the marriage better.
I am a Christian and this is my personal view, I personally think you need to consider what you want to happen and then work at it until you get what you need from the marriage, because the way he is behaving is not normal or acceptable, and the things you want are certainly not unreasonable.
I think it is very sad when marriages break down but I also think it is very sad for people (in your case the woman and children in your marriage) to live in fear of arguments and shouting and criticism.
If you can try and not shout back, but calmly present your case, I think that may help. Also, if he finds it difficult to deal with your emotions, it may help to be as calm as you can, simply because this is the way he will best hear you. This is not because being emotional is wrong, but because sometimes when people communicate in way each other cannot understand it just clouds the issue.
Even if you divorce you will still need to deal with him (because he is the father of your children) and so he will still need to communicate with you as an equal. He is grave danger of losing the love and respect of his own children, and yours if it has not already gone!
I think an outside helper/counseller may be able to get you both to explain how you feel and to move forward. Whether this moving forward is into a better marriage or to be apart or divorce is something only you two will be able to work out. Either a Christian or secular counsellor, your choice. Whoever it is they need to have both your interests as people in mind, not just a desire to keep you together at all costs, IMHO.
I do think we should be happy some of the time and life is to be enjoyed and people respected.
From all you say I don't think it is too late, there is still time for it to change but he must want it to change, not for a day or a week but forever. It may well take work and working as a family together. With failed relationships and other children in his past relationships he may be willing to work at it for the sake of a happier healthier family life.
You sound like a caring woman and I hope you find your husband can value you. The Bible has some wise words but it can also be misused (I feel) to make women feel like doormats! I so much hope you will find a way through this and you must remember you are worth much more than this shoddy treatment. Please allow your Christian faith to strengthen you and not to allow you to be treated as a door mat.
Proverbs 31:10 (English Standard Version) "An excellent wife who can find? She is far more precious than jewels."
You are a jewel and I hope you will find that your husband can grow into the man you wanted to marry, if he cannot, you must choose for yourself what is right to do, for you and your children.
Please do not allow anyone to make you feel guilty for putting yourself and your children above your husband if he is not willing to join you in the work to make your marriage work.