Perhaps you just gained a different perspective when you actually got out and had some fun..
I think that often when there has been a break up people begin to feel that they will never be happy again or find any joy in anything else.. then once they get out and find the world actually hasn't stopped it puts a different perspective on things..
That they are strong enough to go on and they can be happy again without the EX.
Who knows.. as hurtingandconfused suggested, this may be an "up moment" and Yay for real for those!

but it's also possible still to have one of those "down moments" when maybe things aren't looking so great...
I'm going to keep my fingers crossed for you that this "YAY" moment last for you girl!