ok-there are a lot of people being silly on here--but if you are really serious:

Masturbation is normal what makes it abnormal is how often and where it is happening. If you feel it is too much than find a hobby to help fill in the gaps.  You could also set a specific time, like every day after a class when no one is home. If you have a set time you can look forward to it and it might make it easier to slow it down a bit. If you stop "cold-turkey" you might not be able to stop completely.  You are obsessing about this and you might not need to--do you obsess about other things, as well?   Good luck