depressed...

It is only about 3 weeks before the final semester exam and only a few days before my observed long case assessment. Recently, I went to the wards more often compared to the previous posting that i had. However, I still feel that I am lacking of clinical skills. And my knowledge about diseases is so weak that it scared me more of the coming assessment. Last Monday, I don't know why, but I woke up with a most helpless feeling and thought, why am I here? Is it really my fate that i will becoming a doctor one day? Do i have the quality and criteria of becoming a good doctor? Will i do harm to the patients by me becoming a doctor? All these sort of questions came to my mind and had kept me confused and stressed me that i felt like crying and felt like my heart wanted to burst. I really need someone to talk to then but i was going to class that morning. It was no one to be blamed of why I am here as I chose this path in the beginning and it was no one to be blamed if I ever fall down along the way because the most major cause then would be ME! I felt this way and was so down not because i have been tortured by doctors or not because of others but I am really dissapointing myself. I felt like loosing interest in medicine day by day and felt that I need motivation once in a while. Because when i lost interest, i also lost a thing that drive me to study ( in other words, I have become a very lazy person in terms of studying). As my father once told me, even there is something which is hard to achieve, but with interest and desire, they can push me to the goal no matter how hard it is. I can't simply give up now that I'm halfway to my goal and can only move forward. Now, I can only pray to God to lighten up my heart, and help me to open my eyes. That day, I felt a bit better when i met with my friends and talked to them. Sometimes, i think, my condition of staying far from my friends have somehow influenced my emotions and when I meet them, at least they distract me from thinking those 'internal conflict' question. So, family and friends, I really need your words of encouragement or advices to help me through this internal conflict..