Who am I ?

Sometime I feel life is so meaningless and tiring. I always wonder to myself am I a good friend. Am I at least good enough for someone . I'm just someone who is so useless. Why can't I be more confident in myself. Sometime I hate myself a lot that I can think of many funny reason why I don't deserve to be here. Yes it is true I'm a negative person. Cause I can never feel secure and confident about myself. I don't how to be when my life is full of shit.