Damn, I'd love to visit Sweden eh xd (off topic sorry)
So yeah, you see it this way because you are actually scared to get hit. You really should man up and get a hit on him, even if he's older or whatever, just hit hard so he'll remember and even if it's in school, teachers will notice and probably ask what happend, you could simply explain. They probably will laugh yeah but really, do you care about them? They don't, look from this point of view: They bully you because you don't reply back, they'll stop till next time and such on but just really, (if) you have no friends, you have nobody that cares about you, you actually got nothing to lose since you have no goal in life and no shoulders to rest on, well just do it. You are a weak person (no offense), you need to man up and clear this out, if you don't want to fight back just ask why he's doing it and make him look like a fool, they are usually stupid as fuck. I actually remember from when I was little, I used to listen to some oldschool hiphop (oh damn, nas, I fucking enjoy his music, memory lane..
!) and in class our teacher was absent, we were put in some older teenagers class and I remember that skinhead asking me what I was listening to, I didn't answer at first because I know how it would actually end, he took my mp3 and laughed and throw it to me in my face, I almost started to cry but then I was like wtf. (I was young so yeah.. xd) he was sitting in front of me, looking at me and laughing and I just stood up and give him a right punch in his face and I got hit back by a friend of him, he wanted to hit me then but some teachers came... Well it actually ended better than I thought, he apologized to me and few months later he wasn't a "skinhead" anymore, he became a bit more conscious about some things and last time I saw him he even shaked my hand (that was few years ago but still), he was actually friendly, just stupid.
Other thing, stop doing drug, this makes you weak, I don't know how old you are but heroine, cocaine daily (or frequently) is bad for your health (so is weed) but addiction of cocaine and heroine is high, I don't know your financial situation or anything but looking at the picture, you are quite young, how the fuck do you pay your doses? Weird. I know some "friends" could supply you easily but still, I wouldn't want my money to be spent in drugs at this age. But anyway, you look quite healthy for some cocaine/heroine guy, wtf?
Just don't make it worst, stop here. That's a first step.