I think i am a useles person and iam very depressed and sad please help me??

ANSWER:
do not think like that because ur ungrateful to ALLAH by saying that
always think life is a test here we are being tested everyday to see who deserve paradise or hell fire forever
satan ultimate plan is to get u into hell fire forever by putting depressing thoughts in ur mind and emphasizing on the past
in islam we live for every second of the day in order to do good deeds and avoiding sins 
ALLAH SUB HANU WA THALLAH every night HE takes our souls so we are temporary dead during our sleep everyday angel ask ALLAH in order to return the soul to ur body or not if u alive in the morning that means HE is giving chance to repent from sins and do more good deeds and become better muslim everyday
our life is only 60-70 years in the world but next life is eternal forever NO DEATH either in paradise or burning in hell fire nobody will help u in next only ur good deeds will decide what level of paradise forever IN SHAA ALLAH
just stay in wadhu and listen to quran a lot dont let satan whispers into mind and soul.