Feeling Worse

It seems if I have a good day then I am destine to have a bad day.  Is that how it is for everyone else?  If I were to not get excited or over indulge my emotions then I don't go off the deep end? Do we have control over that?  I hate this.  I have had a horrible selling day and I"m really frustrated.  I'm tired. I'm concerned.  ... ARGH!