Did you "lose" this person or did the nature of your relationship simply change, if there is loss what do you believe you have lost?

As the Course says, there is no separation and never was, the only separation that happens is when our ego mind kicks in and tries to convince us (and usually with great success) that we can actually lose something. Anything that can be lost is an illusion anyways, what is TRUE can never be lost, but certainly can be forgotten.

So I think the Course would say: "See what is only true and lose all that is false".

One of my course teacher says:
"Death is walking from one room into another.
We're all in the same house, we just can't see
what's in the next room, and for them they are
entering a different room.

In A Course in Miracles, Jesus says: To protect something set it free. In the Holly Instant you choose, you should pray(ask to the one who knows who is in you): "I give you to the Holy Spirit, as part of myself. I know that you will be released, UNLESS I WONT TO USE YOU TO IMPRISON MYSELF. In the name of MY freedom, I WILL your realease. Because I recognize that we will be released TOGETHER".

I tell you my friend this has worked for me.

I`m glad you got a new point of view.