Dont think im making fun of you...
I spend around 14 hours a day on my computer.
I go to bed around 6am sometimes latter, I wake up...well, when I wake up get something to eat and sit on my computer. Some days I spend almost 24hours straight. Is this good? Of course not. I spend my time playing online games, internet in general, checking my websites and researching more stuff to try to make some buck on the internet.
10 hours a day, for me, is a normal thing, but, I do know im addicted to my computer. It is not only the internet but computer in general, mostly games.
If you live near a coffe shop, make a break, get out. If you can afford to stay too much time on the computer I assume you, dont work, or you have a diferent income. Anyway, treat it like a job is the best thing to do to fight the addiction. It works for me, except when I found out something new to do. I usualy make a break, go eat (sometimes I went to grab food and bring it to my desk), go out to the coffe shop even for 10min drink a beer or a juice or whatever you want.
Also I sugest not to do my mistake. Staying awake all night and sleep by the day.
The worst thing is that we are many hours sitting down. That causes problems. I learned to move more and make time schedules to myself, to eat, to go out, shopping, etc. My computer time is "work time for me". Still, im addicted for sure, but try to control it.