<human>: My girlfriend and I have been together since middle school when we were 14. We're now seniors in High School. Lately she's developed an interest in marijuana and had a desire to smoke it.
I personally have no interest in marijuana (though I do support the legalization of it) however I have lost countless childhood friends throughout my high school career due to the mistakes they've made by abusing the drug and the way weed has changed them. I told my girlfriend that due to unpleasant personal past experiences I've witnessed and been impacted by due to weed that I would not feel comfortable with her being around it and that I wouldn't want her to smoke it. 
She yelled at me (and I mean YELLED at me) that I was being manipulative and controlling by trying to tell her what she can't do and said that if she did do it then she wouldn't tell me. In my opinion, I don't think it's that much to ask my girlfriend not to participate in something that's already illegal to begin with that I don't feel comfortable with due to my past. I don't ask hardly anything of her except for this.
I feel like if she's willing to ignore my one request (which I find rather simple and reasonable) then she doesn't consider my feelings too highly and that there are loads of other more heart breaking things that she would be willing to do without considering how I'd feel (i.e. cheating, cutting, etc). 
I feel like breaking up with her over something like this would be very complicated and probably land me a horrible reputation as "the guy who dumped is childhood girlfriend because of something as trivial as weed". But it's not just about her doing drugs. It's about how lowly she seems to think of me. My girlfriend also mentioned that she has considered taking up cutting due to high anxiety and stress and I feel like if she were to begin destructive habits like that then there would be nothing I could do to stop it because she wouldn't listen to me.

Can you summarize the given text in a few sentences?
<bot>: Gf wants drugs, I'm not comfortable with it, she says I'm manipulative and controlling because of that. Am I really being manipulative or should I handle things differently?