You are around 90% correct.

Correct: we have created an anxiety/depression-inducing society. The fact that we had such societies before does not change that. We also had better ones.

Correct: many/most people live in a (near) constant state of stress, anxiety, apathy or depression

Correct: marijuana and anti-depressants can be used to alleviate the state temporarily

Incorrect: those 2 are not the only methods of coping with modern society. I don't even mean other addictives, alcohol, sex, gambling, video games. There exist real ways of healthy unwinding, coping, building a sort of "resistance". Physical and mental exercises, sports, joga, meditation, spending time with family and friends, self-reflection, journaling, talking about it (even to yourself), screaming (just not at people), physical exertion (produces endorphines!), etc.