Or try to listen to upbeat & happy songs & then try being miserable?
A home renovation or DIY project might be good too.. A girl I know re-painted her room.. Or doing anything she disliked/didn't approve of - as long as it's still constructive. (Someone I know didn't let her boyfriend play table tennis?? OoO or talk to neighbours she disliked, even if they were okay people..)
You can also go look at POF or OKCupid and remember how lucky you are for not being with some of those people there...? (And you could maybe see some nice people are out there too...?)
People who jump into a new relationship too quickly, sometimes don't learn from own mistakes and make'em all over again and sometimes the new relationship doesn't last either.. So maybe remember that?