Yes "Hell" is a state of mind.
But it can be hard to appreciate that when a dreadful condition is imposed on a person, through no fault of their own (or not apparently anyway.)
There are many people and animals already living in "Hell" in one way or another; in terrible conditions where disease and starvation are common, where there is pain and darkness for them. Sometimes the cause is just simply the environment they happened to be born in....or their genetics....
As for the Other World "Hells" -yes they exist. Some are far darker and weirder than we can even imagine. I feel there is no punishing god who takes some there. They are encountered for many different reasons; not always because the hapless traveller is an evil person!
Sometimes they are encountered because a Soul has a mission of service. That is only for the very pure and the very strong.
My opinion is that it is good to be somewhat interested and curious about how things operate. But it is not wise to spend valuable consciousness contemplating "Hell" for most Souls.