the first few minutes of my project disappeared, how can i get it back?

i finally finished a project yesterday and went to the beginning to watch it all back and somehow the first four minutes of it disappeared. all the graphics (text, photos) i put over the edited footage are all still there, but the actual footage of me talking is just gone. that footage was there a day earlier, but somehow during the 12 hours i spent editing yesterday it got deleted.

is there any way to search far back enough in your history to undo a specific action but nothing else? i keep trying to change the number of actions it shows in my history but when i change it from 32 to 100 it doesn’t seem to work; it still shows me just 32.

it’s four minutes of a 50 minute video, but i take so long to edit because i’m not exactly a premiere expert (a premiere pro, if you will, haha), so redoing all of that might take another 30 mins to an hour. my self-imposed deadline was to upload it today. is there any way i can recover this or will i have to do it all again?