random freezing and crashing "crashes instantly when i use split screen"

minecraft is currently very laggy for me i know that the cause is not my internet or device because when i join my single player world it is unplayable for the first minute or so, this has only started a few days ago currently playing on realms is very annoying because i will freeze and crash or i will get lots of small freezes over a period of a few minutes and it results in me crashing. i do have a idea what it might be it when you get to many things in chat like when you do @e in chat it will list all the entities and it sometimes lags depending on the amount of entities you have if you spam this it will eventually crash and it is the same type of crash i am getting, also when i try to do split screen with something like safari it will instantly crash this has not occurred before the 1.14.30 hotfix.