So MAD - help

Laura • Married mother of 2 daughters (11 yrs & 6 weeks) and raising my 15 yr old niece.
Ugh. I feel like I was doing so well for the last few days & now today I'm just MAD & short-tempered about everything again... Stupid stuff. I can't stand this ... as I'm sure no one else around me can stand it either. Not sure what to do though. If I knew how to calm down I would, but nothing seems to help. I just feel out of control. Help!