I like that you started each line with a subject that describes an aspect of yourself. However, the first two lines ended with a locational description (outside, behind), but the third ended on a verb (searching). I was expecting a pattern to be followed, but it was not. Was this intentional?
Not much in the way of imagery, but it does describe you in a way that I can understand.
Good work, but consider tinkering with either the first lines or last to follow a pattern, or avoid one.
It must be hard to write an autobiographical Haiku.
The best approach would probably be some sort of symbolism, since Haiku are supposed to be about nature...
Child on the outside
Implies that you are mature on the inside, does it not? Is this you? An adult in the body of a child? From your age and the fact that you get along nicely here despite your age difference, I would be more inclined to say that you are an adult on the outside, and a "Child on the inside"
The other lines didn't really trigger any alarm bells, they seem fine to me.
--Q
"I wish not to be understood, but to understand...I wish not to be loved, but to love!"
--Clare of Assissi