Has someone really deleted my sheet ?

Hi,

I am currently working on a school project with fellow classmates and let's say... We really don't get along well and I am scared they might try to sabotage me (which they actually want someone heard they want to punish me by making me having a worse grade than them I don't know how but guess they want to do so by making it seem like I don't contribute at all)

My sheet was deleted on the shared excel we have, you can see on the bottom left (what's my arrow pointing at in both screenshots) that my part "Entretien Dplômée 2" isn't here anymore after someone did a modification yesterday at Midnight 1:04 am whereas it was here on the 15th of March, when I last worked and finished my part. My sheet isn't here still... Is it the person that logged in yesterday (I think so because my sheet was still here atleast 4 days ago I had checked just in case) ? Problem is, the change isn't shown in "Show changes". It goes from "Modification brought on the 11th march --> Modification yesterday at 11:39 AM. Am I just being paranoiac or has someone definitely deleted my sheet (specifically the person that opened the file yesterday during the night) ?

(We use whatever's excel latest version)

Before

After