It's hard to let go of something, or someone, that you love. Like the teddy bear that you've snuggled with so many times that all the stitches that make up his smile have fallen apart and are mere threads sticking up from teddy's face in all different directions. You've put a lot of love into that little bear.
but I guess, we all have to move on, at some point or another. Whether it be getting married and eventually sticking teddy in the closet, or on a nearby dresser. Or letting a child move out to University and make her or his own decisions. Or whether it be distancing yourself a bit from a close friendship so that he or she can move on to a new, more intimate, relationship. All are difficult. And you never really feel ready to let go.
I guess what needs to happen is for you to realize that, occasionally, loving someone is letting them go. And while it may be difficult, and I'll admit that I have cried trying to do it, it's often also freeing, in a sense. Freeing you to give the unknown into God's hands, and say, "Hey, I have this void now and I'm feeling kind of lost. Please fill it for me." And then letting him do his great handiwork.
And surprise! Something much better comes along. And takes your breath away. :)