While it is impossible for me to offer a diagnosis based on what you’ve said I can make a very strong suggestion that your mom take your brother for an evaluation by a psychiatrist, clinical or neuropsychologist. These professionals are trained in doing evaluations that can help pinpoint the problem, and more importantly make recommendations about the potential solution.
His age, birth order, high temperature, sweating, verbal abuse, physical violence, inconsolability, and extended episodes are a collection of symptoms you’ll want to have a professional evaluate. It is not likely for him to improve without some outside help.
He is lucky to have a sister that cares as much as you do. Thanks for writing us.
Wishing you patience and peace,
Proof Positive Blog @ PsychCentral