And hating yourself makes things better, how?

Apologize to him? Tell HIM you don't know what happened, you have no idea what snapped in you. . . see if he'll help you try and figure it out? Maybe he said or did something to remind you of your lovely lab partner; the whole fight-with-boss-go-home-kick-dog thing is not a "joke", that actually happens. See if you can see what happened in your case. Yes your reaction was out of your ordinary (and both of you do/should know that!) but look on the bright side; you damaged property, not another person.

And why would you be looking at the "next" time and "How can I ever say anything about him blowing up over nothing?" as if that's your "normal" job? Realize that you now have grounds for compassion