If you really are stuck, ask someone about it and don't leave it until the day before the exam. In Physics 2, every problem in the example sheets will be discussed in a lecture, tutorial, or supervision period, or a solution will be made available for you to refer to. Make yourself a timetable to regulate your study. Stick to it when you can, but don't be a slave to it. Put everything on your timetable lectures, labs, supervisions, when you go swimming or go out.
Summaries Make summaries.
This allows you to get all the stuff in perspective and to ignore the details. Long and complicated proofs can be reduced to a few headings. It is also extremely useful for revision purposes, and you can review an entire course in a few minutes if you have a good summary. Be prepared to make more than one summary. Your first try, when you don't fully understand the work, may turn out to be misleading and emphasise the wrong points.