Conflicted about friends drug use??

Me and a close friend have both been weed smokers since before we knew each other.
Over the time we've known each other we have both helped each other cut down on our weed use to about once/twice a week. (he was smoking daily before he met me)
anyways......being that I'm a STRICTLY POT ONLY user, I don't condone any other drugs. N tbh, I barely condone weed, I wish I never started/ or started become a weekly toker.
My thing is I think we should able ourselves to become as naturally "high" as possible without having to use drugs at all.

This is where the conflict begins, he likes to use "uppers" aswell as weed, he will take MD, Xtacy, and/or Coke if hes out with his mates who do that kinda stuff.
I on the other hand - HATE ALL drugs except weed. I honestly feel like there is a danger to people believing that M.J is 100% not physically addictive - which causes more people to take it and become MENTALLY addicted but hey, I'm no fucking scientist.
The thing is - now he's begun using these things around me and it makes me EXTREMELY uncomfortable. He becomes really happy (before hes even sniffed) and then loud- annoying and abit obnoxious while hes on his coke high.
Now, he says to me - "Its like weed, its not physically addictive, it only becomes bad once your doing it like EVERY night" I dont really say anything to him because I really and truly know NOTHING about cocaine facts like I do with weed.

My dilemma.I WANT him to stop taking MD, coke, X around me!!! AND I WANT to tell him the truth: - Coke will probably A) kill you B) drain you of all money and inspiration - look at the dream we were sold about weed that NOTHING can go wrong because "its onlllyyyyy weeeddddd" and look how hard we had to WORK at cutting down our use, if coke makes you this happy its going to be EVEN WORSE then when you tried weed man!!!!!!
........but I just sound like a hypocrite.
I dont know any facts about cocaine or what it does to your body ALL i know is that people become addicted and FUCK UP there money and lives. + even that may not be the truth.

side note - the most I've seen him use it(indoors around me) before was once or twice a month. Since the new year I've seen him take it(indoors/around me) about 3/4 times a month. this is COKE im on about here. Soo I cant really say he's "addicted" as such but his character is that of someone who will DEFINITELY be addicted if hes not already within a few months.
I'm already noticing his personality change and hes becoming alot more interested in taking MD and COKE then he ever has been. e.g. I'll see him after he been out on md,x, coke for a weekend, and he describes regular events like they were the GREATEST EVENT IN THE WORLD because he was soooooooooooooo high when w/e it was happened, and he cant wait to do it again. It makes me sick but also sad at the same time?? I feel soo fucking conflicted.
TBH - I'm starting to not like him. His identity is starting to merge with the things he does while high. He gets soooo happy from even HAVING coke,md around in the vicinity. N in general he's become alot less "conscious" of himself and how he acts (sober). Also, (sober) hes getting BITCHY as HELLLLL. Everything a problem that never an issue when hes not high (on weed or otherwise).

So how (as a WEED USER) can I tell my friend to stop using this drug I know nothing about around me......or completely. If he doesnt stop it soon - I will have to cut him off. but weve been good friend for a couple years soo I dont wanna have to do that :(

P.S- one of my biggest issues is he OFFERS this SHIT to me. he says he feels gulity NOT giving me some while hes on it. I tell him everytime to NOT FUCKING OFFER ME THAT SHIT. and if I ask to NEVER GIVE IT TO ME. (my fear is I will try it and become addicted as I have a addictive personality to pleasure/highs)
this is a serious one sooo please help me guys.
we are both 21 y.o in college/university.