I've been having intrusive thoughts about becoming addicted to drugs - my brain sends me scenarios of being addicted as well as what it might be like in recovery, and I imagine feeling humiliated by the experience. These thoughts started after I read a few articles about others' experiences with addiction, so since then, my brain has thrown these thoughts at me (not too often, most days than not, but they're brief, lasting only a few minutes). Thus, it's become my worst fear nowadays. 

I have no history of contact with alcohol/drugs. Before this fear set in, I guess I can describe my mindset around substances as regarding almost as substances that are foreign to me, and bad - they aren't part of my world, only others use them, so I still would've had no inclination to engage with them.

The aspects around addiction that drive my fears include fear of losing control (of drug use, in this case), and especially the humiliation and stigma/misperception around addicts (not great to think about as a socially anxious person).

I don't know if my anxiety is warranted in this case, because addiction is something that's rational to fear, since it greatly affects one's quality of life. However, I keep thinking about it as if it could happen any time in the future - except I can't control or predict the future. There's nothing in the present that warrants the anxiety (not around drugs or anything); my brain just repeatedly sends the worry "What if this happens to you?", but I can't really do anything about it. It's just keeps sending intrusive thoughts about it. I'm tired of it, but lately I've had another worry on top of it: What if I'm not worrying enough, or I should worry at the rate I am now? It's tiring, but addiction is technically something to be feared (it's just my brain sending me thoughts about it out of context).