Pixel, I went through a situation similar where I needed to get work done, but I enjoyed the server too much. The simple solution I took was I updated my minecraft profile so it wasn't compatible with the version Famcraft ran so that I couldn't just quickly log on (for some reason those "I'll get on for 5-10 minutes" always turns into 2 hours). I still would get into IRC, but I mainly had the window minimized while I was working on whatever paper I had to write for my classes. Every so often I would take a short break (normally after having typed out 1/2 to a full page), chat a bit in IRC (5-10 minutes, and I used a timer to keep me from going too long) then get back to work. It worked out well for me, and let me still feel like I was staying active in the Famcraft Community and not just visiting the forums.
Another thing I did when I was teaching was I set aside 2 evenings a week (Monday thru Thursday) where I would get an hour each night before going to bed to play video games to help me unwind. Friday was another evening for gaming as well, with Saturday being when I was hanging out with friends all day, and Sunday was prep day for the upcoming week. But those 2 nights of playing games, sometimes for as little as 20 minutes made a huge difference in my mental state and helped keep my stress levels down. Granted, during other periods, like when I was grading papers, or working on lesson plans, I was usually lurking in IRC.
I hope this is helpful to you in helping you in your quest for finding self-control and schoolwork completeness.