Your brother’s symptoms are concerning but without meeting him in person, I can’t identify a specific diagnosis. Over the Internet, it’s impossible to diagnose psychological conditions.
He checks multiple items to ensure that “everything is secure.” How often does this occur? If he checked his car and house locks once, or even several times a day, that would be normal. If he checked them 30 times a day, that would be abnormal and potentially a sign of obsessive-compulsive disorder.
I’m not sure I fully understand what you mean when you say that he randomly clenches his fists and moves his arms as if he is “venting anger waves.” Perhaps that is his way of physically expressing his overwhelming feelings of anger and rage.
His insomnia, his realization that his symptoms are worsening, and his belief that he is “disturbed and scared that he will randomly snap and lose control,” are all deeply concerning. Those may be signs of psychosis but he might be simply on the verge of losing control, perhaps due to anger and rage.
Determining the reason why he’s about to lose control is less important than preventing a violent incident. What matters most, at this point in time, is that he receives immediate help.
Your brother has told you that he fears that he may lose control. That means he’s on the verge of potentially harming someone and legitimately fears that it will happen. This is a warning sign. He is asking for help.
If he’s willing to be evaluated by a mental health professional, then take him immediately. He should also be evaluated by a physician to rule out a physical cause.
If you believe that he may be in imminent danger of hurting himself or someone else, then take him to a hospital or call 911. They can protect your brother from harming himself or someone else. Don’t hesitate to call the authorities if necessary. The best option may be to call the local mental health crisis team. They can come to the home, assess his behavior and determine the appropriate course of treatment.
Please be safe and don’t hesitate to write again if you have additional questions. Please take care.
Dr. Kristina Randle