Instead of apologizing for something you did, just say, "Sorry we ended up arguing yesterday." and then go on to something else. You will be acknowledging that it isn't cool, but not putting the blame on either of you.
Take a clue from our hubbies: now is your time to withdraw a little bit.
My simple advice: rubber band. It really worked for me.
Me: 42/H: 37 T: 10 years/M: 8 D9, S8 Bomb: 7.23.07 Separated: 1.20.08 D Final 3.19.09 Affair started in '05, found out parts in 11/07. They married 11.26.09