So youre telling me the aunt, who is supposedly tight with him and sees him a lot, every other weekend iirc in previous chapters. But she was contemt with him staying like that, potentially for good? Really? Through all those years she just look at my guy withering his emotions away, she just gonna watch as he soulessly live his life, turning all his friends and family away? Has she never consider maybe getting a professional therapist involve, instead of straight up mentaly crippled the guy.
To her, him being Emotionally locked away was better than him ending his life.
Plus, seeking professional help isn't always the solution, especially in case of people who are far more intelligent even if they are broken inside.
Because they can figure out stuff easily and usually take it up in a negative and far damaging way. Like in this case, MC acted normally with his Aunt, because she never hurt him, which in a way allowed him to maintain his own existence. But if she had taken him to a professional, MC might have considered it as her also abandoning him like his mother & sister.
Also, most of the time, seeking professional help ends up in putting people on medications, making them possibly dependent on them for life, which isn't good, because that isn't cure.
There is also the fact that, each countries has their own systems on how psychological cases are handled. And in case of MC, his case was so bad that he might probably have been locked away in some facilities away from everyone. Aka., he would have been all alone and probably never be able to have any sense of normal life.
While the Aunt's method wasn't perfect or didn't have it's problem, but it still allowed MC to stay alive and have some sense of normalcy in his daily life.
Like MC was able to take part in club activities during his middle school and even do better and actually started to feel a sense of accomplishment (until stuff happened).
Just to add, the Aunt is in a way a professional (her profession is related to psychology), but when she tried to find solution for MC's mental health all those years back, she reacted more emotionally and used a solution which at that time felt more viable, because it was a simple suggestion. The reason her solution failed wasn't because of her bad decision, it was because MC's luck was really bad with Women.
One can compare it to a doctor prescribing the best medication to a patient, only for that patient to suddenly become allergic to it without any warning (something that patient didn't have when the doctor prescribed it), and there was no way to undo the damage other than wait and let it heal naturally.