Am i the only one?

Having a good family, good friend group, people that will support me trough though times but still feeling like a total mess.

I have nothing to complain about and I still feeling depressed and i dont see the point in life. I dont know why I am thinking like this. I just feel so empty.
I have no reason to feeling me like this but i still do like everyday. Its been years i feel like this, going to a psychologist, talking about mental problems but I am always getting back in this depression mental state.
Does this feeling goes away? Is really the only reason that I am still alive because i dont want to ruin my parents life? I dont know how long I can live like this. Always living for someone elses happiness instead of mine own, feeling like you disappoint everyone. 

I just dont know why I am feeling like this, i have no reason to be depressed but I'm still am.