Apparently you are more "emotionally invested" in the relationship than he is. There's no reason for mature adults to constantly be "on and off" in a relationship. Your statement, "I love him and I am willing to fight to stay with him.." "shouldn't he do the same?" Your real questions should be...
"Why do I insist on staying in a relationship with a man who is (clearly not as committed to it) as I am?"
If you want something different, YOU have to do something different.
You'll know when you've met "the one" because he will also recognize you as being "the one"! True love is about (meeting) in the middle and not (chasing). Based upon what you have written it doesn't sound like he's "the one" for you.
Best of luck!