can i say "i've lost you" to mean "you've lost me" ?
ie. "sorry, you've lost me. can you explain?"
One example, 'I have lost you' can express the idea that you are following a group of people through the forest and suddently you see a deer, you watch it during a little time, and after you don't see the group, you have lost the group. (the group doesn't have make any action to lose you in the forest).
Hope it's more clear now for you.
Have a nice day.