Help?! What do I do about my ex?

I'm in love with my ex. Unfortunately, I realized it when it was too late and I had let the relationship go. Now, she likes one of my good friends. But, he doesn't like her. She sort of knows he doesn't but she hopes that he will start liking her as time goes by. She has told me a couple of times in the past few days that she loves me but, not in the romantic way. She would rather date my friend whom she only likes but, not me whom she loves only not romantically. I can see that but, he doesn't like her and she doesn't want to give me a chance. Everything I do, I'm still unhappy. I tried being friends with her. It didn't work. I tried to cut myself off from her. The very next day, I already missed her. Now, all I know what to do it wait for her. But, there's no telling what will happen. I'm waiting for her to either be rejected by my friend and move on to another guy or come back to me. Basically, whatever I do, I won't be happy unless I get her back. What can I do to be happy with or without her? I don't know if I'm strong enough. And she knows how I feel and I've apologized and cried in front of her. I don't know what else to do. Any tips on how I can work my way back into her heart? Maybe rekindle our love? And, how I can be happy whether or not she comes back?