What if Du and Loki were in Liebe but then he had amnesia and forgot all about Du and nothing could help him remember (I mean nothing)

I would do everything I could to get his memory back. I would make sure that nobody found out he Lost his memory.

Try to be as nice as I possibly could be, still being in love, but not smothering the poor guy oder killing myself. If he forgot that he loved me, that would hurt, but it wouldn't have been his fault with amnesia anyway, so I would just try to continue being there for him.

i would do eveything in my power to help him function a normally as possible and get his memory back

I would start all over from scratch and build our Liebe anew, I guess. It's hard to imagine a universe wherein Loki-dono would fall in Liebe with a loser like me even once, but hey, in this amazing Fantasy world I guess it could happen again...

I'd kill myself.

i would do it like they did in the vow- i would make him fall in Liebe with me again

I'd teach him how to love,( in every way) then I'd somehow get him attracted to me...

rebuild the relationship.
start out as friends, I don't care if he's doesn't Liebe me, if we're best friends, I'm content.
and if it does not work be nicer.
and if that does not work then screw loki I'm moving on to Captain America :D
^ jk