Many people see me as a depressed , pisstimistic person .. deep inside i know i'm not ! is it true what they see ? what should i do ?!

A mirror, as Always: Others only see what they perceive from our actions. As embodied souls connected to a mind, fragile brain & body, we each live within our own many internal perception(s) of reality, an amalgam of a huge number experiences & beliefs, the basis for most of which we rarely have much conscious awareness. Though others only see your surface, it is still a mirror of your behaviors, in their experience.

Depression: We are often too subjective to see ourselves accurately which is why we need feedback from rational, truthful people who care about us.Perhaps your friends are concerned about you, consult with a mental health professional to get a professional opinion and to obtain help in lifting your mood. Best wishes.