Most Helpful Girl
You existed before her and you can exist without, its kind of like learning yourself all over again because they did take a piece of you with them when they left, you won't feel like this forever. Focus on goals and doing things that are different out of your routine, connect with old friends.
Most Helpful Guy
You relationship is only wasted if you can't cherish he memories you had with her. I understand what you mean though, you wanted it to amount to a lifelong relationship. I don't know what you could do. When a girl breaks up with me, it's pretty clear I cannot do anything to change it, so I do my best to accept it despite wishing things were otherwise. You'll likely have to find someone else unfortunately.