How to edit length of a project (sequence duration) in Premiere Rush

Hi all.

I am completely new to editing and creating videos, so I apologise in advance for my poor description of the issue i am facing, but here goes...

I have a project that i've created which has five 'layers' of images / text that move and transition into one another. The total duration of the actual project is 30.4 seconds, however, when I export my video as an .mp4 file (the format i want), the video goes for 1.49 minutes; the screen goes black after my 30 sec clip ends. I have searched high and low for setting that allows me to change the length of my project (not the length of my clips). Note, the clips all end at 30.4 seconds, nothing extends past that, but the Sequence Duration is 1.49 minutes (see attached screen shot). I thought the sequence duration would be impacted by the duration of the clips, but that doesnt appear to be the case. Is there any way of shortening the sequence duration?

Someone. Please. Please. Help. Me...