Serious Editing Help

I spent about 8 hours editing a long video after my final save after adding an ending clip to playlist (I’m unsure if it makes a difference but it wasn’t in the timeline yet). After this save happened all video and audio was shifted about 5 second, meaning if I cut up times second 1 thru 30 to seconds 2-3, 7-10, and 15-25 are now seconds 7-8.12-15, and 20-30. I tried ctrl-z and looking for ways to fix this but was unsuccessful. I plan on redoing all the editing because I do need to get better at editing but I would like to know a way to fix this in case it happens in the future.

I hope I provided enough information for someone to understand what is happening. Thank you all.