hello,

Best thing to do while studying to avoid distraction from gadgets is turn them off and keep them away. You can also use some restriction apps available on play store. These app restricts uses to you phone for the time you set. As far as the concern for bad videos goes, it is natural and happens in teenage. But it shouldn't affect your studies.

Best thing is to turn your phone off. Make a plan for you day which should include that you have this much to study and complete your target. Make studying a game of completing target this will help you focus.

Hope this was helpful.