I cannot play on my created world please help me

have been playing in my minecraft world (survival) for almost 2000 hours. It used to crash and close the program frequently but without any further problem, it would load again. Yesterday it crashed and now it won't load anymore. I have noticed that for some users this happens and they can not play in any world or even load the game, but for me it happens only with this world, since I tried to create a new world and there were no problems with it. What happens is that whenever i try to get into my world, it starts loading but then crashes, before even getting into the world, with the message "The software was closed because an error ocurred". I have tried to load it around 100 times by now and it won't load. I checked for corrupted data but nothing was found and I still have enough space on the game and on my switch. I tried downloading minecraft again and it didn't fix it. I have done everything I could think of and nothing seems to work. If there is any solution for this, please help me, I am losing a lot of progress