only you know if you are ready to open up and discuss your feelings with either your parents, or with a doctor/counsellor etc, ..
have you tried confronting the very reasons you feel depressed, and what was the outcome, .. what is it that makes you feel low, what keeps you focussed, what are your interests etc, ..
being depressed is not fun ("really? wow, what a shock" i hear you say) - i've been currently on medication for ages, had counsellors, mental health assessments done, and now have a member of the CATT (crisis and treatment team) guys out each day to administer meds to go along with my anti-depressants. I have found them to be brilliant, and are really supportive, and there if i need to get away from everything and go and have a chat for a half hour over a cuppa etc... maybe ask your doc to see if your local hospital has a CATT section operating that could help you when you're at your lowest ebb.