So, first thing you will learn is that less is certainly more.
The highest I've ever gotten is from snapper hits out of my bong. Hit it and quit it you could say. This is a great way to initially cut down and make the transition easier. I find when I've tried to quit in the past, I go on a huge binge the night before, smoke all my weed and kief. I then wake up the next day feeling like shit, which initially helps me stay sober because it makes me view pot in a negative way. However, my metabolism is very fast. So once I clear it out of my blood and the cloudy headed feeling goes away, I feel my brain start to work up the "reward" section to encourage me to smoke, and then the justification starts and before you know it I'm toking again, feeling completely justified (and foolish at the same time), the cycle continues.
I'm cutting down right now as well. I have college to focus on and quite frankly I'm sick of being stuck in the habit. I think the best way to come about it is to list off reasons you want to cut down (for me, I want to stop during the week because I am a full time student involved in many activities and even though I'm not stoned during the day, I feel like the residual effects build up and overall having it in my life everyday is very stressful and unnecessary, and it inhibits my social behavior).
-I don't like feeling stoned all the time even when I'm sober
-I don't like inhibiting what my brain is capable of when I need to focus on success
-It's damn expensive and I don't have the money
-The high is hardly rewarding. It almost feels more like an obligation at this point then true recreation.
-I'M NOT QUITTING FOR GOOD. I am confident that learning to appreciate sobriety and the benefits of moderation will be motivation enough to cut down.
OP: sounds like you have some good ideas. Exercise is GREAT. Healthy diet has always helped me. Try some meditation. Whether you are spiritual or not, it helps me a lot. Exercise (and possibly meditation) have been clinically proven(I know exercise has) to decrease cravings in heavy cannabis abusers. Think of it this way; save being a stoner for the times in your life you can afford it. Since I am still a full time student with financial support from my family, I have breaks to look forward to. Winter break, for example, will be a full month where I can be back home with all my high school friends and have big sessions like we used to. AND IT WILL FEEL MORE REWARDING THIS TIME. Because I won't need to feel guilty about excess, because I worked hard and can finally reap the benefits of my break.
Find other things to do when your roomies smoke, you might actually find you feel better about yourself for resisting the temptation on a regular basis.
Sometimes I think we smoke a lot to relive the past. The good ol' days when it was a bit more fun. Just remember heavier consumption will not lead to any more satisfaction. Many people on this board and past cannabis users can usually agree that less is more, and that you feel overall better when your body returns to equilibrium. Just have a goal to work towards OP. I think you will be surprised at the results. Don't think of it as just a "t-break", because once it ends you will psychologically try to compensate for all the lost time because sobriety will feel like a prison sentence to you. Think of it as actively working to improve your life and also your cannabis consumption.
It's a special drug my friend. You can make it special again. Just know that I'm in the same boat as you right now