I feel like such a looser all the time. I've tried everything. I feel so hopeless now, more so than before. I'm very sorry you feel the way you do, it's a terrible way to feel. The average age of onset of bipolar illness is 18 years old.
Many people become ill much younger than that.
The youngest case I know of was at two years old. But that is extremely unusual. There are four general categories of symptoms. There are symptoms of mood, thinking, sleep and energy and behavior. In depression the mood is flat apathetic, dulled, irritable, and hopeless.