This is what happens when resentment festers. Don't feel bad about it - after 10 years, it had to happen and now finally your relationship can move forward! So congrats on that
As for your husband, he may not be as angry as you think, but perhaps he is as shaken as you and needs to sort through his feelings.
Tell your husband you need to talk about your MIL, and set a date for tomorrow (or tonight, if you are both calm enough). As soon as may be, before his parents get to him first.
During this discussion, agree in advance that the past cannot be undone and there will be no finger pointing. Just team work on how to make sure it never happens again.
This will be where you marshal your arguments of:
- you and DH as a team, unified against everybody, specifically the ILs on both sides. You have to consult each other and back each other up in front of family and friends.
- you will snap again in the future, or not allow her in the house, or not allow her access to the kids, if MIL does not stop disrespecting you.
- no DIL has to take any abuse from their MIL in the 21st century, so your husband can let go of that right now. That said, please be reasonable and let go of as many things as possible!