i called out with covid because i couldn’t handle working 46 hour weeks and needed a break

my work is now asking for proof of covid and i don’t have it because i don’t have covid, i’m just exhausted and i don’t have a union so they rejected my request for days off previously. this was the only thing i could think of in the moment what do i do now? this is the only place i could think of to post this because of how fucked up the situation is