Heavy weight of the game world

Hello! I am playing Minecraft for Android Bedrock edition, encountered a problem. My friend and I decided to survive in the ordinary world without any cheats to complete all the Xbox achievements. ..during the game we traveled a lot and in the end we started having very terrible lags, our world currently weighs 52 mb, which is a lot for my device! ..as far as we understand, this problem is associated with not unloading chunks from RAM after exiting the world. ..and after a few days the world became unsuitable for survival, it is very insulting, because we don't want to lose all the resources that we have extracted, please solve this problem! ..