Reduce the time spent in distractions. You don't have to stop them altogether, just reduce the time gradually each day. After every hour of study, reward yourself with a break. More importantly, let go of any guilt about wasting study time. You are not a bad person for wasting time. Tell yourself, whatever time has been wasted in distractions is gone. Nothing can be done about it. Now, make sure you don't spend more time in activities that don't help you in the exams. Stop avoiding the hard work of studying and preparing for exams. The more you avoid, the harder it gets. Instead, take small bites at studies. Divide your studies into small, manageable chunks. Take up these chunks one by one. You will accomplish more this way. Once you start making these changes, your sleep will improve as a result of less and less tension. I hope this helps. Take care.