Think my boyfriend is a secret alcoholic and drug addict

So my boyfriend is always drinking and smoking weed. We are long distance 2 hours between us so we don’t see each other much but when I see him he drinks and smokes so much makes me worried for when I’m not around. He usually smokes between 11-20 joints a day but he only starts smoking late about 6pm and usually had 1-2 full bottles of rum. I feel like this is so excessive also the next day he isn’t hung over or anything and is able to drive the 2 hour journey home which makes me think he is used to drinking that much. I know he smokes all the time even when I’m not there but I’m not sure wether he drinks as often or not. I’m worried because I don’t want to be with someone who is reliant on drugs and alcohol. He is also a different person when he is sober he can get angry at me really quickly or be on his phone constantly ignoring me but when he is high or drunk can’t get enough of me always saying he loves me wanting to cuddle and kiss. What is you guys opinion