If you need help right now.

If someone is in immediate physical danger, call 999 or go to the nearest hospital emergency department. You do not need to be sure it is serious enough. That is theirs to judge, not yours.

If you are the one supporting someone else, you are allowed to find it frightening. Stay with them and make the call. You do not have to know what to say.

Worth checking: your workplace. Many companies in Singapore run an Employee Assistance Programme, which usually covers a number of counselling sessions at no cost to you and separately from your manager. It is often in the staff handbook or on the HR portal under benefits. People forget it is there.