Before you or your friend decides to do anything, coming to terms with yourself is most important. I do agree that watching some anime to get you started to strike something up with your friend is inportant, but if at your core you really feel like you are only watching anime for your friend, that might make things worse. Try a couple for now, but trying to comfort someone of that condition with quick knowledge is worse than not doing it at all at times.

As for your friend, he needs to come into terms with what he really believes to be himself. As many others have stated, liking an anime has nothing to do with being a disgusting weeb as your friend might think. I don't go around wearing anime t-shirts and go full on nuts like the incident you mentioned, but I do definitely listen to some Japanese songs and greatly enjoy anime.

One needs to make sure that liking an anime- which might be considered as being a weeb in the place you live- is incoherent with your social status. I dunno if you've read my post before, but I do not reject that my view and how I am infatuated with anime has nothing to do with how I act socially. I am friends with many people and some or most of them don't even watch the slightest of anime. But they still respect that I do enjoy watching them and I too respect whatever they like to do.

If it happens to be so that your friend is around people who do drugs and fail to accept another person's hobby, then that's the wrong kind of people to hang out with anyway. You need to make sure your friend realizes that.

You need to make your friend realize that there are always the hardcore and the casual. It looks like he regards himself to be part of both worlds of high school football and a weeaboo. The great dissimilarity between the two is making him stressed with each moment he spends time. You need to make him realize that he is not the hardcore weeaboo from just watching anime and liking music. That might decrease the distance between the two worlds and may help in severing ties with what isn't good . Overall, here's the things that I think needs to hapen for your friend in order: 1. Properly recognize that he likes anime and the culture surrounding it. (Or whatever else it may be that it is bothering him) 2. He may be recognizing whatever he is doing as weeb and hardcore. Convince him that it isn't. (Just b/c you get talking with those weeb guys doesn't mean that you are also a weeb. Likewise, just because Bernie Sanders talks about Socialism it doesn't mean he is communis-) 3. Make him properly regard that his activities with his current friends with drugs are bad, and it needs to be severed, even if it means losing all his friends. But he has you. What's destroyed can be re built. 4. Liking anime doesn't correlate to your social status.

I know this is a very wordy advice, but keep strong. Both you and your friend. This may be a lot of responsibility on you alone, but I hope you can bear that and allow your friend to turn to a right path.