I'm sorry this ended for you.
Don't try and be friends with her. It will only prolong your healing and will eventually be uncomfortable when you start dating others. Ask her to come and get her stuff. Be nice about it, but remember that you're not a free storage unit.
Try to not put too much emphasis on her reason for leaving. Sometimes it can be really hard to pinpoint the actual reason and so the reason we quote is sometimes not entirely accurate. In your case, her not being so affectionate could have been part of the problem/symptom of the problem. The only thing that really matters is to accept that they no longer want to be in the relationship.
It will be tough for a bit, but you'll get through it. Good luck
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.