Your course mentor / tutor should provide you with practice tests.
If the problem is exam nerves rather than knowledge these can often be helped by repeated exposure to (simulated) exam conditions. Any test will do. E.g., if you like Star Wars, google 'free multiple choice test star wars' then take it under 'exam conditions' with a clock ticking away. After a dozen or so exercises like this you will have got acclimatised to the 'stress hormones' and instead of panicking will find they actually help your focus and performance for the task in hand.
Also, read every question carefully both before and after you think you have found the answer.