..I hide depression..what can happen to me if i hide it any longer?

i feel like exploding. the only reason i dont wanna die is cus im scared of the afterlife..i tell people im not depressed n i acted happy for the sake of others. i went to a mental care center n i lied to them saying i was perfectly fine. if i dont lie to my family, they say ima faker and im selfish n makes it worse i also lie about my sexual orientation cus my family is homophobics my friends know though,n my friends become emo posers. its so stupid. but idk how much longer i can hold it in. ive told 2 of my best friends ut they dont know how to help, they try n change the subject.n then after a lil ill forget n im ok. until night i cant sleep n i cry..n i try not to cut cus ppl call me an emo-_-..can something and happen to my brain if i hide my emotions?