Sometimes it is quite hard to maintain my focus on learning and studying. I find myself checking mail, reading social media commentary and avoiding the still to be worked on assignments. What can I do to prevent that?

I break up my studying into steps. Make sure there are no notifications on, remove your cell phone if necessary, And then study for 30 minutes, and reward yourself with 10 minutes of surfing the net or whatever you want.

I’m a life long student and my advice is first to see the joy in learning and studying. Don’t study for the sake of studying or passing the test. This is about you being an even better you. Start small, with 15 minutes per subject a day, set a timer. You may find you want more than that 15 minutes ; don’t stop your flow.
Social media is a way to put things off and puts the brakes on flow. Limit your exposure to 15 minutes a day. That is how I decided to get off social media entirely. I have way more time for everything else that is important, including sleep!
If you find yourself checking your feed. Redirect that into some exercise or a quick walk outside. Something that get you up and moving rather then sitting and scanning.