Sorry about the copy and paste but I was MNing with someone else about not losing your cool, as I found I was turning into a shouty and abrupt parent. It might not be relevent but I thought I'd post it just in case.
"1-2-3 Magic is posted about on MN occasionally.
It's basically calm, non-confrontational counting with a significant pause for the child to reflect and stop whatever misbehaviour they're involved in. When/if you get to 3 the consequence takes place, e.g quiet time in her bedroom or whatever you deem appropriate, allowing them and you time to cool down.
It works if you have too many parenting styles in place, have lost control completely or, in the case of my ds he gets so enraged that he can't hear to be reasoned with, and we also now do it with dd who is just 3, as if she's told no she does it even more with a big grin on her face!
It's simple and doesn't take up much emotional energy which is the best thing, you#re not left feeling ragged. But we try to balance it too, as you sound like you do, with empathy, acknowledging his/her feelings and plenty of cuddles too."
Hope you feel better soon.