It depends. Sometimes the problem is in what you are avoiding to do. Sometimes the problem is in what you are doing instead. In your specific situation, the problem may be avoiding the book, or it may be inability to turn off FB.
I guess most people will assume that you have problem reading the book, which is where various motivators, plans, TO DOs, Pomodoros, etc. can help. So I will give you the other half of the advice... that maybe your problem, to put it bluntly, is internet addiction.
Analogy -- if someone has an alcohol addiction, and they refuse to admit it, they will probably only describe some consequences, e.g. "I have problems talking with my family" or "I have problems focusing on my work" etc. And they can get a lot of good advice about family communication or work management, but none of the advice will work, because none of it addresses the main problem: that the person gets drunk in the morning every day. But if they are asking for an advice in a pub, there will likely be a taboo against discussing alcohol addiction; too sensitive topic, too many people will get defensive. -- For similar reasons, speaking about internet addiction on a web discussion forum is kind of a taboo. Too many people have it, too many people deny it.
To check whether you are addicted on not, try to avoid internet for one week. If you need it for your work, then use it strictly for work purposes, and not a hyperlink more! If at this moment you say "impossible", then you really really need it.
If my diagnosis is correct and you try it, the first hour or two of free time offline will feel like a mental torture. But then you will find yourself able to do other things. And you will be surprised how long the days became again, and how much you can do in one day without internet. To avoid self-deception, you could use a calendar where you will note whether you used internet for idle browsing the given day or not, and how many offline things have you done during the day. The relation between those data will tell you a lot.
