First of all, you should tell only to people that you are sure that they have the same values as you. To people you can really trust. If you tell to people without the same values as you, you will find some problems to explain your situation and they will mess up you. So, please, do not tell your situation, thoughts and any other thing to people you can not trust. Tell only to people that you are sure they will understand you. To people that use the same language as you. To people that have the same values as you and have the same way of think you have. If you are too ashamed to do this to people around you (even if you know that they will help you, but you are not sure at all), go to a strange place (very far from your home) and tell your thoughts to a random strange. He or she will disappear soon and you will never be recognized. But be careful to choose...
Once you know for who you will tell, you have got to think how. You can write a short note explaining what is your addiction, the studies about that, the side effects and with the common QA or mistakes. Then, your history. It is all about rhetoric. Train your speech in front of a mirror and make sure that people will understand what you are saying. You can use metaphors to tell things you do not want to say directly.
And the most important: why are you telling this to someone? What you want?