World Achievements broken

So I've had this world for like at least 5years, and now it's broken. It's broken by achievements not working anymore, I know for a fact that I didn't turn on creative or activate cheats so idk what happened.No matter what I do and am told nothing is working. Even if I did I didn't mean to. This world meant a lot for me, I wanted to get every single achievement on this world but now it's ruined. I've now became suicidal again, pls just fix my world.