I think what you did is right, provided that your classmate is what you described, it's better to put some pressure on him before it's too late. If your classmate is a wise man, he will still thank you. If he is not satisfied with you, it is not your problem. Don't blame yourself. The kinder a person is, the easier it is to take responsibility on himself.

To be a man is to have such a principle, and everything must have a bottom line.

Don't think too much, no one will really think of you, except your relatives.