Video and audio disappeared from the timeline

[Johnathon273642918bhp]

I was editing video from one sequence to another sequence. The first sequence had nested clips in it and I would set an in and out point on the nested clip and copy the portion I wanted into a second sequence. As I was pasting a clip into the second sequence something happened where all the footage in the second sequence dissapeared and the nested clip opened as a sequence in a new tab. I tried ctrl + z to get the footage back but the history tab has no record of me deleting anything. 

any ideas to get the footage back? Thanks

[Johnathon273642918bhp]

There is no auto save from the time of the project. I already checked.