Part of me thinks you did realise how you were coming across to the waiter as you said you were using your clipped teacher voice. Why fake an authoritive voice on when speaking to a waiter?
Like I say, if it's a one off and a symptom have having a load of other things going on as well, your dh could have been gentler in telling you that you need to apologise and be shocked as its out of character for you.
If you speak to others like that often then it's not right and maybe dp doesn't want to tiptoe around the rudeness.
Your dp should have told you to apologise, and I'm pleased you are. If it's a true one off then he could have been gentler about it.
If I want blunt answers and aggressive responses know where to find them now!
But this makes it sound like you want allowances made for your own bluntness and aggressiveness, while not stopping to think that others posting here and being blunt may well be also having a hard personal life.
Some posters here will have been in the service industry and spoken to several times a day by people putting in their clipped teachers voices and know that most people use those voices with them because they think they are better than them, which is bad enough , but when your having personal problems and having people speak to you like you are beneath them while not being able to tell them to fuck off makes it so much harder, you got to leave the resteraunt and have a breather, that waiter had to move on to the next client and smile while probably feeling like utter shit inside.