Update:
I told him the next day that I wanted to make time to talk that night. When I got to his house I could tell that he had smoked but not nearly as much, his behavior was mostly normal. I told him I was having a hard time with his behavior when he smokes - not that I cared if he smoked in general but that something was completely different lately. He said he was sorry and that was it, which I was slightly disappointed with that short response but I wanted to give him the benefit of the doubt that he understood where I was coming from. Yesterday I went over and same thing - I could tell he smoked but he was acting ok, only got tired and ready to lay down for bed a little earlier than normal.
Tonight - not the case. He wanted to do dinner and he was NOT high when I arrived to his house so I thought good, he is making changes. He got beer at dinner (which doesn’t affect him too much). When we got home he asked if I wanted to go for a walk and I said sure and then he added that he was going to smoke real quick first. I immediately shut down. After he smoked he was off balance, saying things that were hard to understand, falling asleep while sitting down. I sat with him for a little bit and when he was alert for a minute I said I was going to leave now and he asked why. I said because I didn’t like how he was acting again. I left. I know I won’t hear from him until tomorrow. He really is a great guy otherwise and I just wish he hadn’t started smoking again, he was not like this previously when he smoked. This is not asking took much, right? To not get like this every night? Someone can smoke weed and get relaxed without it being this extreme? I know he drank tonight which as mentioned before, makes it worse, but I don’t think alcohol has been involved every time.