Generally, we can divide mental disorders in two groups for basic understanding purposes. One is a soft mental disorder. It includes anxiety and mild forms of depression. The other is hard mental disorders such as severe depression, mania and different forms of psychosis. Symptomatically, to understand it in simpler form, in soft mental disorders a person doesn’t completely disconnect from reality, whereas in hard mental disorders, they are disconnected with reality in one or many aspects of life. People with psychosis may also have hallucinations.
Hearing about your situation, I understand your son and daughter-in-law leaving home after their marriage has been quite stressful. That has the potential to make mental disorders worse and might also trigger anxiety and depression. If you are predisposed to it, it may also lead to psychosis. To get to the root of the problem we need to evaluate in detail as aggressive or irritable behavior might be a symptom of milder mental disorders such as anxiety and depression but it might also be present in harder mental disorders. Usually, the intensity of symptoms differs. Since you mentioned that you didn’t recognize your own sister, tried to hurt yourself, and were admitted at a rehabilitation center, I would say you need expert care and guidance. To be honest, we don’t usually recommend anyone to be admitted to rehabilitation centers in Nepal as they don’t have proper psychiatric care. However, there are a few good rehabilitation centers. But after hearing what you’ve said, I can say without a doubt that you need to seek professional support—a psychiatrist, to be precise. Only when there’s proper diagnosis, can we start looking for solutions. In your case, it’s best not to resort to solving the issue on your own. Whatever degree of complexity an illness might have, diagnosis and some form of support are always possible. If only you could get rid of your aggression and suicidal thoughts, you could hopefully improve your family environment too. The sooner you see a psychiatrist, the better.