This girl has ruined me, but I'm not going to let her go.
Sorry to hear that. What did she do to ruin you?
She told me that she no longer loves me.
While it will be very hard, if someone tells you they no longer love you then you should let them go. If they miss you then they'll come back, but if not then you should find someone who does love you. It's not healthy to hang onto others like that.
Nah, she'll come back.
I understand you still cherish this relationship, but I think it's healthier to know when to let go. Don't you want to be happy and free of your situation? You might be missing out on someone who is more compatible with you.