I wasn't planning on starting today but I guess that's just my AvPD manifesting.
I will avoid doing the things that you mentioned and also play video games. I will only use the computer for university related matters and watching my usual TV series (can't really watch them on TV). I will visit facebook once or twice a day because my friends usually make plans there and sometimes it's also university related. If there's no notification regarding that I'll just close the browser.
I'm going to set the hours at which I can watch my TV shows so I don't waste time on the internet while waiting for them to come out. I'll choose an inconvenient hour (like before dinner) so I don't stay on the computer the rest of the afternoon.
Great! I'll be back in two weeks and ask you how it went!
I'm going to logout right now and my apologies to the OP for overpopulating the thread with my posts!