What do you do?

when you have given someone everything you have inside you and it still is not enough. Do you stay or walk away?
I am so drained emotionally. I mean that I really feel so empty now. All of the ups and downs have taken their toll on me.
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You make me want to give up on loving you, on being your friend. In my heart I feel that no matter what I do it will never be enough. If you want me you are going to have to come and get me because me coming to you is no longer an option. I have invested alot of time and energy into you. I am done.
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I will not pass up another chance for someone to meet my needs. He does not make idle promises. He communicates effectively. He loves me unconditionally. He does what he says he will do.

But I am a fool, because I love you. But even a fool can see the sun on a cloudy day if they look hard enough. He is the sun and I fear that if I continue to put him off he will sun on someone else's day. If you don't step up, I will be gone. Forever!