I'm going to throw my friend into a mental breakdown
why would you want to do that?
I want to teach him a lesson
If you have problems with your friends just stay away from them. It's not right to get back at them. It'll do no good.
I'm tired of this shit. I don't give a shit about how he feels. I just want to see him broken.
I understand wanting to cause someone else to feel hurt, but it does not help you in the long run and will make you feel bad later. You should just cut off contact with them, instead of actively causing harm.