Just don't close yourself off from finding new love. Don't build any walls to avoid getting hurt again, cuz in the long run that hurts so much more than anything else. Stay open, do your best to go out and meet new people. Hang with friends a lot, stay busy, keep your mind off of your ex. Learn something new, a new skill, get a new hobby, take a class, start working out, learn about and invest in stock, do something new to your car...
Mainly just stay busy, you'll find that when you stop and let your mind wander you're thoughts will eventually go back to her... this is normal, but it sucks and after awhile you'll find you won't even really be thinking about her anymore. I'm sorry to hear that happened to you man, I went through similar shit a year ago and the one thing that helped me more than anything was meeting new people and doing something new everyday.