Last night was fun! :-)
Therefore, today I am sad. :-(
Not sad for any particular reason, just sad because I used wine and beer and vodka to deplete my brain's dopamine reserves... the only cure for which is time.
While Googling for some evidence to support this theory about hangover sadness, I came across this neat chart comparing the effects and mechanisms of various (recreational) drugs.
According to it, alcohol:
"Opens BK potassium channels (hyperpolarizing neurons), closes SK potassium channels in reward center of brain (causing DA release), probably other effects"
So remember kids, never make life altering decisions the day after a party! Your judgement is impaired and things almost certainly aren't as bad as they seem.