addicted to cannabis
That's almost like being addicted to coffee.
>my roommates they don't allow me more then 3 hours of sleep a night
I don't understand what you mean by that. Are they literally in the same room as you? If the sleeping problem is related to light, get something to put over your eyes. If it is related to noise, what causes the noise, music or films or games? Can you get them to use headphones? Are they talking, what is it? How about ear plugs? (If you need a clock signal to wake up, there are also visual alarm clocks and shaking alarm clocks you can put inside your pillow and even smell-releasing alarm clocks.) A decent combo of stuff like the above can be had for less than 50 dollars. Bonus question: Are you also doing things like that so that other people can't sleep? When everybody is doing shit like this, it seems pointless to change one's own habits to make things easier for others, since there will be noise anyway.