Why can't we just get along

Today has been a rough day.  I've been sick for days and I'm so wore out.  It was my scheduled day off so I ran errands.  I met my wife and kids for dinner, my wife and I had our usual spat of something incredulously stupid.  I determined tonight she is like her mother and yells or speaks in an exasperated tone almost all the time.  I am not sure of they are constantly exasperated or not, but they always sound that way.  So generally when I respond I tend to be a bit short/exasperated back because I feel her tone is not warranted.  I know I should do better and I'm going to try to do better and not argue as much with her and try to be calmer but I have done that for years and it's not had great results either. I just need out!  The worst of it all, is she thinks our relationship is OK.  It's not great but she think it's stable.  Stable my ass!  I need mental rest from her.  I need to get some of my debts paid down so I can find her a house ASAP.