Big mistake. I have one word for you: bridesmaids. Weddings are excellent opportunities to meet people, flirt, etc. (There’s lots of good stuff in that “etc.”, some of it naked. :D)
Everyone is different, but sometimes after a breakup, the best thing you can do is use opportunities like this to flirt and play more than you would in your normal surroundings.
Well, Manda, there’s a difference between having more fun with a date and insisting on bringing a date. Besides, I’ve always figured that if you don’t know a single other person in the bride or groom’s life, you probably aren’t close enough to them to attend the wedding. If you’re a coworker, you’ll have other coworkers to talk to. Out of town cousins would, again, be in the bosom of their own families.
If you honestly care about the bride or groom, but don’t know one single other person at the wedding, take the opportunity to get to know the other people they care about. If you can’t do that with good grace and take honest pleasure in your friend’s happiness, then you should stay home and send a gift later.
Weddings are one of the best places for a single guy to pick up women. Honestly and swear to god. If I was single, I would have no problem going solo whatsoever. Actually, the wedding I went to this past weekend I almost wished I still was! MY GOD 
(Just try to make sure they’re not family… that would be a little weird…)
Seriously, weddings are great for single people. I mean, look at the advantages:
BTW, as an aside, to young single guys (like college-aged): take a ballroom dance class. Even though I’ve never used any of the dance steps I learned in the class I took, the basics of leading a partner are very handy in the wedding situation.
I’ve been to more weddings w/out a date/SO than with one, and it’s really no big deal. Some were family weddings, some were weddings of friends. If it matters, I’m female. If I were you, I’d go alone.
Go stag and have fun. The last time I did, the groom’s aunt dragged me, heels leaving grooves in the dance floor all the way and that with the bride pushing me, over to meet her recently divorced son.
We had a wonderful time. Weddings can be fun.
I second that piece of advice. I’ve seen George Costanza-types become the studs of the dancefloor if they know a couple of steps.