Movie Maker Problem: Splitting Video Deletes All Clips

Pain in the butt, but hopefully someone can help me out. 
As a rising YouTuber, I am trying to keep a consistent uploading schedule in the hopes of gaining more subscribers, as I am very close to another milestone I set for myself. 

Yesterday I played a video game that I didn't enjoy very much, on account of its repetitive gameplay, I played for over an hour so I knew there would be a lot of footage that was unnecessary that I could cut out and hopefully make a much better video. 

But after I got over 20 or so minutes into the video, as I proceeded to remove specific clips, my movie maker decided it had, had enough of this and now every time I split it takes all the clips away, shortcuts such as Ctrl + Z do not work to undo what was done, but the edit undo does. 

This is very frustrating as I do not have the income at the moment to be able to purchase anything fancier and my CPTSD (Complex Post Traumatic Stress Disorder) is going haywire as a result of this frustration. 

Has anyone got any solutions on how I can fix this, I save my project every few minutes to make sure the edits I have done are kept. 

Thanks
Brisingrize.