First of all, I'm so sorry that you and your husband are having difficulties. Whoever first said that marriage is WORK, wasn't lying.
To answer your question on what I will tolerate in my marriage. I guess the answer for me is that I won't tolerate being disrespected. By actions or by words. I know in a marriage there are ups and downs and at times, let's be honest, we might not like our spouses very much. While I always love my husband, there have been times when I didn't like him very much. However, I've always known that he respected me, even when we are having a rough patch.
I think most people have said/done things that they wish they could take back. THings that were said in anger and meant to wound. Perhaps there was an underlying hurt or frustration that caused your husband to lash out that way. Who knows.
I do know this.....it sounds like your problems aren't related to this one event or comment. As hard as it is, I think you have to take a few steps back and examine your relationship and determine what positives are you getting from it. Do you feel respected, do you feel valued, are you happy? If the answer is no, then you have to decide if you are willing to put the work into it to turn those answers to a yes. And most importantly, do you have a partner who is willing to put in the work with you. It takes 2 people to damage a relationship and it will take 2 people to fix it. If your husband is unwilling to even discuss things with you, then I think you have to think hard about that.
I wish you all the best and sincerely hope you guys can work it out. Good luck!