Postcard mail merge address problem

I have a postcard someone created in a landscape orientation with two
postcards per page. I am needing to address these postcards using mail merge
with a different address per postcard.

Settings: half-page, address only (because I now have the hard copy and need
to only print the addresses), multiple pages.

When I do my mail merge I end up with the same address per page. I need a
different address per postcard in each sheet . Help!!