Corrupt world AGAIN

My world once AGAIN has been corrupted. I don't understand what is causing this issue but i would appreciate it if it could get fixed because im sick of spending literal MONTHS on builds, just for them to disappear. The castle that has taken me 6 MONTHS to build is just gone. When i joined into the world i was spawned at the correct coordinates but the castle was literally just gone. Same place, same coordinates but of course, again, the build that ive spent 6 months on is gone. Funny how every time this happens the only thing corrupted/ gone is the build. So, i would appreciate it if you could fix/explain whats happening because, at this point, making builds is pointless because every time i build something it gets corrupted or the world, somehow, gets deleted. I created a back up copy of the world accouple months ago but i had built SO MUCH since copying the world, meaning ive lost HALF MY BUILD. I can not explain how annoyed i am. I love Minecraft but if this keeps happening (Which it will, since Mojang never seems to fix the issue) im just going to stop playing because this is such a huge waste of my time. I come home from school to destress and relax by playing Minecraft but then after MONTHS of building, it just gets corrupted. So, thanks for the added stress. .