Black bars appear on the sides of the video not just top

Hi there, noob question sorry.

I have footage I want to edit and then export in the 2.35.1 aspect ratio. ie watch on my TV with black bars top and bottom, but NO black bars on the side.

I changed the aspect ratio of my sequence to 3840 x 1634 per directions, but when watching on my TV or youtube it is with black bars top and bottom as well as the sides. 

What have I done wrong?

My second attempt at an edit, so much to learn! 

Thank you for your patience.