I drank more than I should have growing up but once I moved out it stopped, idk what happened but I guess I had other priorities. And yeah, being surrounded by complete wastes will only bring you down.
I studied in college and for a while my performance was slipping miserably because of the kind of people I was around. I got my shit back together though and managed to save my education pretty well. Think about this then, you mentioned your sister took blow too and you grew up with a lot of peer pressure. Careful who you associate with then, if you want to get out of your cycle then try associate less with those who partake in alcoholism and so on...>space rock
I realize what I said now. Yeah man, crack and heroin are the last place you want to be and it is the last place you ever will be. My old friend got hooked on crack and holy shit he was a mess. He is in rehab now but his entire life is gone so stay away from that wacky shit. You don't need me to tell you though, you already know this.
LSD isn't so bad though and things like weed are alright too. Less harmful and you still get a good time out of it. If you're still doing this from stress, try switching to smoking a tobacco pipe or shisha; they're probably more enjoyable than rotten old fags.
What I meant earlier about enjoying your time is just sort of making your own time of this world. Doesn't have to be drugs, maybe just travelling around and seeing what this world has to offer.