3 year old daughter

I have a 3 year old girl and shes getting to me bad.  My husband and I are at wits end
She is constantly in a state of change.
She in one minute will be the sweetest little girl, and the next she is whining, crying, and just downright unrully, and then back again all day long. This is driving me crazy.
Im a stay home mom and I am here for them but its getting to me bad My stress level goes as quick as she does and i dont know how to control her or even if this is what she needs. we constantly fight about this condition(?) and i sometimes feel like walking away and not looking back. this wont happen but this really hurts. she doesnt sleep and when she does she wakes up screaming for me and will wake the other children (we have 3) .
this happens every night. i dont remember when we both have had a good nights sleep i think its been 3 years
if you can give me an inkling of advice it would be appreciated

[Kevin Kennedy, Ph.D.]

This age can be difficult. We often hear about the so-called Terrible Twos, but actually more children have such instability after they turn three than they do when they turn two. This might simply be a normal-spectrum situation, but it may be more than that. You'd be doing a sensible thing by seeking an evaluation with a pediatric mental health professional, who can assess the situation and advise you accrdingly.