1.) Tell them how you feel. Just because the relationship is over doesn't mean that you can't be friends. The things that you two enjoyed are still things you two can share. Watch a movie. Listen to music. Just keep in mind that things may not get better. People break up everyday. There are other people out there with similar qualities of your ex.
2.) Fake it. You're going to feel bad for a while. Don't let it consume you. Pretend you're having fun. Suprisingly, and eventually, you will!
3.) Get out of that house. It's hard to forget something that you have to see all of the time.
4.) Punch her in the back of the head. She deserves it*
*don't punch her in the back of the head. She doesn't deserve it. A year isn't really that long. It may be a good thing that you two broke up. Find out what went wrong with this relationship. Was she the problem, or were you? Use this time to better yourself. You'll make better choices next time.
