As far as your falling confidence goes. Well the hard work that you put in for the past 8 months or so will go in vain if you dont realise that the last 10–15 days are like a blank cheque for your hard work. In other words the more you revise now, the more you will be able to cash in on your hard work and be able to get a good rank. So I say if you dont have confidence have fear, fear of failing.
Mind you fear and depression are two different things. Depression is with no or less hope. Fear is just a recognition of the danger and serves you well as a driving force. Dont lose hope because you practically have completed the race, just take a few deep breaths and complete what you started. If you cant do it for yourself, do it for your parents. You will soon see your fear turning into confidence as you revise 🙂
In good faith,