Chica has the same problem with her Chi.

I am not sure these suggestions will help.

1:: start leaving her for a few minutes and gradualy increase it to more.
2:: ignore her when you leave.
3:: ignore her for a few minutes when you first get back home.
4:: Try to have a schedule. Dogs get use to a set scedule and
seem not to stress as much. (untill you break it.)

Good luck. I guess if nothing works you can add another
small dog to your household for a companion.