Help me please!

How the hell am I supposed to decide whether to stay and keep trying with a guy or say "you know what! Enough is enough." It always ends the same and I'm so sick of feeling hurt all the time. I just don't want to give up just yet. I honestly am so head over heels for this guy. But he can't see that and Golly I sound like a love sick puppy. Can someone just knock some sense into me please!