Here's a relational truth I've learned through the years, a truth I've passed on to many people. It's a hard lesson to learn. But if you learn it, it will possibly save you much pain. Here it is: if you love someone with all your heart and they love you with half their heart, move on! If you find yourself giving all you have to another person you love and that person is only reciprocating with half a heart, move on!
Don't subject yourself continually to this kind of abuse. The problem is their half effort makes you believe that one day, somehow, they will eventually give you everything they have. But it most likely will never happen. One day you'll wake up with vain regrets and wish you'd found someone who loved you with all he/she had.
It's a lesson too many have had to learn the hard way. I hope you won't have to. Here is is again: if you love someone with all your heart and they love you with half their heart, move on! Save yourself tons of pain!