why does it hurt so much if its the right thing to do?

if something is right to do, why does it have to hurt sometimes?
i may know that its the right thing to do, but i don't want to,
i know i need to pursue other avenues, and try to make them work,
if it doesn't seem like its going to then i will get out,
why is there so much hurt when doing the right thing,
especially when it comes to loving someone?
loving somoeone so much, but knowing you shouldn't or cannot be with them,
just don't want to let go,
it's to hard to let go,
scared to let go,
why do i have to,
why did this happen, if its not right?
Damn Love!