I think some people are being too hard on mchalel.
I'm sure she's probably given herself some of the same advice she's received on this forum, yet has been unable to follow it. I know I gave myself some excellent advice early on in my relationship, yet because I was young, inexperienced, and suffering from low-self esteem I couldn't follow it.
I keep thinking of that line from Disney's "Alice in Wonderland".
"I give myself very good advice, but I very seldom follow it."
mchalel, you're still young. Use the emotional pain you're feeling now as a tool for gaining very valuable experience. What I'd suggest, (you're probably thinking right now, "Great MORE advice"

), is to first stop beating yourself up for what's happened. Time only flows in ONE DIRECTION, you cannot change the past, just as your boyfriend couldn't change his. Instead of looking at what's happened as a tragedy, try, (and this will be difficult), to view it as something you can turn to your advantage, put the knowledge you've gained to the best use you can.
Then step back and take a BREAK from dating, all dating. Go out with friends, maybe even find a female friend you can take a short trip with, (not to scout out guys, but to relax). Try to think about what's happened and see if what you can learn from it.
And also go to therapy. Many people view therapy as something only "crazy people" need, but I feel nearly EVERYONE can benefit from an 'emotional tune up'. Just as people go for yearly medical checkups to ensure good physical health, they can go to therapy to help promote good mental health.
As always, I wish you the best.