what will happen if my love fades away from the one who i loved so much ?

you need to ask yourself why. and what are you going to do about it. then ask your partner about it so it will be fix. or if you both feel the same way, maybe it is time to separate.

It is easy, you need to do is, to remember why we love him/her. Then update your intentions regarding your relationship. Mutual honest with each other, and accept him/her as is. Hopefully your relationship gets better. If it is ultimately unable to stay together, and then let it go, then he's/she’s not your real soul mate.