What you were doing was big enough to go straight to reporting. The way he saw you as a person probably changed. Its really not surprising he didn’t talk to you first.
I mean if you were sharing homework answers or olds test, or even cheating on your own test that would be different. You were compltly doing others homework for money. You keep saying that they still did the tests. Well depending on the class, the homework is a big part of the grade. Not to mention all the added free time they get by not doing homework. Extra time to study, less stress, and a boost to their grade. Plus you were doing this for money, not to help a friend or so they would help you with yours. AND it was multiple people, many times throughout the class. On scale of severity, what you did isn’t the absolute worst possible but it’s getting close.