Great post of actual opium shipments - about 10 million pounds sterling per year.
So with your 100 million Chinese addicts, that’s about 2 shillings a year per user.
Either that’s some cheap smack, or your number of addicts is off by a factor of say...an order of magnitude or two.
Existential crisis? Hah!
Or your assumptions are off, as well as your understanding of history.
China's form of government lasted several thousand years. It didn't survive the social collapse caused by massive and widespread drug addiction. China was so weak that the much smaller nation of Japan invaded and very nearly conquered it. Were it not for American help, they would have.