le Internet. big distraction. you aint le only one.
I get distracted all the time. What I do is I have this extension on Chrome called "StayFocused". It allows you to enter in the sites you want to be allowed and the sites you don't want to be allowed. Then theres a time limit for the not allowed sites and yeah. See for yourself.
If you don't use Chrome, then the best I can say is to just have some self-discipline. Yep that's all I have to say
Study with a more serious friend. Agree to let them slap you with a ruler if you drift off into space. Also, give yourself time for breaks. Say, watch a youtube video after every so many pages of reading or after so many math problems. Time yourself so you don't spend too much time online.
Don't spend all day one topic. Do a little of one subject and then switch to a different class. I can study mechanics for 3 hours without a break, but my mind drifts if I read physics for more than 15 minutes. So I mix them up.
Tell yourself, today I will do x, y, and z. If I get done, I'm not touching anything else! Tomorrow, I'll look at a, b, and c. Set short term goals if your attention span is low.
I study for finals in my quiet room, alone, with video game music, but some people get restless without enough noise around them. So make sure you're studying in an environment that's good for you. Find out what keeps you motivated.