How To CHILL OUT

Ive always been calm, never have I ever been a yeller buuut lately with my 3 kids (16yrs,5yrs,3 yrs), work,school, housework(my house sooo bad) and building new home Ive been so overwhelmed! Today I yelled at my 3 kids literally all day :( I would have a huge outburst then try and correct by calming down and apologizing but by that time its too late,theyre already upset! I yelled so much and so loud that my throat hurts and I feel terrible about it. Any tips and tricks on how to calm down when my triggers are all day long?