yea man, I know the feeling!
It's just natural for blokes to feel like this from time to time [women too assumedly!]....but it will pass.
I guess there are a few options you could take. You could ride it out. In a day or two you'll probably feel much better.....Or you could revisit the "clouds and the rain"!
...shall we say!......or you could express how you feel somehow in a painting or song or write it out....or if you wanted to do something about it, you could take some steps and try joining a dating site or a club or go to a pub or try saying hello to someone you like or some other kind of active step toward meeting new people.
You've got this energy inside you atm which can be a very healthy, motivating thing, and is better than feeling numb....but it's up to you where you decide to focus that energy.