Have you ever lashed out at someone so badly and hurt them without realizing? How do you get past it when you realize it?

I am in a spiral of self hate and unable to change the situation at all. I get the ‘you learned at least and move on’, distract yourself etc. (not working). 

I’m asking for tips in the here and now. Learning and change is a long game. I am wound up af and don’t know what to do with myself. 

Please help, thanks