As contra productive as this may sound initially, there are apps for that. If you have any idea how much time per day you want to spend on certain apps (with the time amount for studying in mind), you can set perimeters for those apps (Insta, YouTube, Netflix, Facebook, etc.). That way you get warned before the number of minutes/hours are almost finished. After that they’re closed for the day (that is, those pesky apps). You can circumvent it, but that would mean kidding yourself. You need to be dedicated (which you already might be because you came here to ask about it).