Hamster you make a good suggestion regarding the note on the back of the front door. It can compliment what I've said before leaving the house ("I'm going to go out, we can talk later when things are less heated"). It would reinforce what I have said.
Rose that's a good point re behaving in the same manner. I do at times shout back (well raise my voice as I have a sott voice) saying don't speak to me like that, don't shout at me or alternatively snap back. Then am told not to be snappy - and then I point out you snap at me. But he'll deny that he gets angry or make excuses (i'm sore and tired etc etc) to which I've said I've asked you to do something about it (I've initiated lots of talks about his soreness and tiredness encouraging him to talk and trying to move it onto what can you do to address this).
Somone suggested I draw attention to the double standards which again he doesn't want to see. For example he'll sit around on the couch doing nothing then get annoyed at me going on the computer but my saying well how about we go out and do something he'll say no so it's either do I say you're sitting on the couch so my going on the computer is no different to that which will then escalate the situation o just leave it.
I think that using the leaving the house when it gets heated technique would leave to my having reduced anxiety about saying the wrong thing, standing up for myself when he has a go at me and reducing that walking on eggshells feeling.