I guess...I am in the same situation as you, except that I am a
girl, and the person I can't give up on is my close frens. In fact,
the fact that my feelings for him have lasted all these years,
astounded me. I have gone out with other guys several times (just
got out from a r/s myself actually), but everytime, my feelings for
the other guys will die out after a while, and my feeling for this
close friend of mine will be revived.
So I guess for now I am still his close frens, like you, I have
also confessed and got rejected cos he said I am just like his
sister, nothing else. So I resolved to being his good friend and
tried to control my feelings for him everytime we are together.
Nothing else can be done I guess, at least when we are still frens,
I can still have a reason to care and show my concern for him
sometimes.
Guess, since we can't get rid of the feeling inside our heart, we
can just wait, see if something can actually come out from this, or
maybe time will help us to wipe it away from our heart one day.