Once upon a time when I was going through a particularly nasty breakup, a dear friend gave me a piece of advice. He told me, "
Throw yourself into your work."
In retrospect, this was good advice for the following reasons -
First of all, it keeps you busy and your mind on something [else] productive. Secondly, it increases your self-esteem when you do something, do it well, and can take pride in it. And finally, maybe you have some ambition and might like to move up the ladder. Being good at what you do will always help in that regard.
I, of course, took his advice to the extreme and became focused on my job to the exclusion of everything else, lol. Please don't do that; just know that his advice really does work.
What has happened to you is a reflection of your date's character and says nothing at all about you - except maybe that you really got lucky and dodged a bullet. Whew!
Try to force yourself to go to work tomorrow. It won't do you any good to stay home and fixate on it.
(I realize this is easier said than done, of course, so take what you can from my advice and leave the rest; but please do try to realize that the problem isn't yours).