My advice is: Don't be bitter. Just STOP IT. It's not healthy, it's destructive.
You might think "well, that was a waste of time." It's not true. Hopefully you learned something about yourself and about relationships/dating. You learned what you can do better next time, or you learned what NOT to do again. There's an upside.
My music taste wouldn't be as broad as it is without all the guys I've dated.
To each of the guys I've dated in the past two and a half years: It may not have worked out between us, but because of you, my music collection is much better than it was before I met you. Thanks for introducing me to: Bon Iver, Incubus, Alison Krauss, Silversun Pickups, Mason Jennings, Nickel Creek, the Avett Brothers, Herbie Hancock, Band of Horses, Led Zepplin, Sigur Ros, Stravinsky, Noah and the Whale, Ryan Adams, Brumby, Andrew Bird, Relient K, Greg Holden, Cage the Elephant, Dexys Midnight Runners, Yann Tiersen, and Tom Tykwer.
See? There's always an upside. Look for it.