The dark side of Occlumency: Severus Snape
I see fics always talk about Occlumency like it’s a super power, Sherlock Holmes Esq mind palace. But think about it in different terms
Bottling up your emotions (possibly for years) could cause you to go crazy from the stimulus if you release that cork at once.
Projecting a false self to fool a legimens could cause a split in your personality, not being able to tell who the real “you” is.
Perfect organization of your memory could cause mental problems like OCD or similar.
If you go with the common perfect memory angle you have the problem of being able to recall all of that trauma you’ve gone through in perfect detail knowing the full emotional weight.
Not to mention in general how dangerous it would be to mess with the organization of your mind, especially turning it into a 3D space vs the conceptual space it was previously, who knows what unintended consequences there could be!