Oh, man, I am so sorry! I know the feeling so well, from my breakup a few years ago. It feels like you wanna rip your heart out of your chest. The expression 'broken heart' is exactly how it feels.
You asked if you should remember negative stuff? Hell no. You had a good relationship with some rocky times, and it was a good thing ... give yourself some moments to grieve, and just let the feelings flow. Don't let it go on and on,,, it may overwhelm you at times, and you need to feel the pain to get thru it. But have a cry or whatever when you need to, then say, 'okay, time to get on with my day'. Don't throw anything out, just pack it away like Shania said. You will want your remembrances for when you can look at them. And like Avi said (love ya, Avi!), whatever you do, don't get into a relationship soon.
Have a good nite with your brothers. I'm glad you're not gonna be alone tonight.
xo
tal