Last year, he reported me to the college because I was doing students’ homework for them for some extra cash. He said that what I was doing was depreciating his Diploma. I guess I get it, but what kind of friend would try to get me in trouble for something as harmless as doing people’s homework?

One who believed that you had already betrayed him, apparently. That’s not an excuse for ongoing harassment, though.

In many academic institutions, including some of the highest reputed engineering schools, your former friend would have been considered equally guilty if he failed to report your academic dishonesty. Asking you to quit cheating would not be an acceptable alternative; that would be concealing your violation.

Dude is still being a harasser, which is also unacceptable conduct. Two wrongs don’t make a right. But you’re still pretending you did nothing wrong. That’s not super great either.