I have mental health issues. I do?

I am 18 years old ,preparing for neet competitive exam ,I am a dropper ,still I am unable to study sincerely, I just go in these depressive phase after a point when I don't see marks improvement where I leave studying and just do timepass a lot ,its been 4 months I have not studied exams are coming and in 11th and 12th also i didn't study for 7 months in row and 3months  am i a bipolar ?,i am still procrastinating and being lazy,is this  procastination and laziness result of  childhood trauma ,I have grown up in very toxic environment ,quarrels going on ,I am always sad and depressed never happy  and i am victim of substance abuse i just get addicted to social media and try to escape from reality  ,how should I heal myself ,I want to have good career and good future life I want to MBBS ,and in our area mental health issues are considered taboo ,so my parents also don't understand me ,they don't take me to psychologist or psychatrist, they don't feel safe about them ,what should I do?