At some point you will realize that you

have done too much for someone

that the only possible next step to do 

is to stop. Leave them alone.

Walk away. It's not like you're giving

up, and shouldn't try. It's just that you 

have to draw the line of determination

from desperation. What is truly yours 

would eventually be yours, and what 

is not, no matter how hard you try, will never be.