God doesn't command or condone the use of medicine in the Bible, and you are hardly using it for medicine, less harmful drugs would work fine. The Bible says to both honor the body God gave you and to not alter your mindstate. There are very orthodoxical Christians that refuse any form of modern medicine for this reason. To say God is commanding you to use marijuana is stupid, to say he commands you to use marijuana when it also breaks the law is retarded.
You are performing mental gymnastics. Your argument about the Romans forging God's word could be said of the entire New Testament, including the illogical demonization of homosexuality. The Bible was written by men and it reflects the cultures and eras they lived in. The stories of the New Testament were passed down orally for 70-200 years (depending on chapter) before being written down by scholars. If you've ever played the game 'telephone' you'd know how much personal views/bias and cultural norms were injected into the stories. The NT was compiled by the Roman Catholic Church around 200 BCE (AD). They gathered writings from across the Roman Empire and compiled a story they thought was both coherent enough and also purveyed their ideals and social/political agenda. They created a new religion to both pacify and unify the vastly different cultures and religions in the regions that the Romans occupied. They changed dates of holidays, they created the idea of holy trinity instead kf a singular God, they created the idea of a human incarnation of God (Jesus), and they borrowed many more religious symbolisms from the religions of their conquered territories. Try doing some reading on that.
As a side note, one of the worst parts of Christianity IMO is the idea that all people are inherently evil from birth, and the idea that "you can't pick and choose the morals you find logical or question anything" is psychotic.
Cementing the idea that people are inherently evil/sinners as a foundational block of Christianity gives people an excuse to behave immorally - "I shouldn't have done that but I'm only human." It also gives them a false sense of justification and forgiveness - people will go on being horrible human beings their entire lives but still believe that any wrong they do will be forgiven. It teaches people that they are naturally greedy/selfish and so are others, psychologically detering acts of good will, generosity, and charity. It teaches people that they need God to be a good person, that it isn't a choice they make or have the strength to make on their own; it paints humans as powerless to their emotions and thoughts.
Teaching people to not question God or the Bible simply makes no sense except in a practical way to deter detractors/criticism/dissent and independent thought/analysis. It is anti-intellectual and anti-science. It is a measure of control. Every person interpets literally everything in life differently than anyone else, the same goes for religion and religious doctrines like the Bible. Look how many different denominations (different interpretations) of Christianity there are (Catholic, orthodox, presbytarian, methodist, baptist, etc.). All of those denominations came from a different interpretation meaning they questioned and dissented.
If there was a God he would employ the very logic we possess. So tell me, what is immoral, logically, about homosexuality? Think on this one.