Lyric discussion by fr0st2k 

Cover art for Kitchen Sink lyrics by Twenty One Pilots

A kitchen sink -- I feel like he's expressing that everyone has their own way of dealing with things and feeling some way.

In his inner circle, or his world, a kitchen sink means something specific...its his thing, and he believes everyone should have their own thing. (I personally feel like a kitchen sink, for him, relates to the saying, "everything but the kitchen sink." Referencing the kitchen sink being 'left out' and alone. So when he references that he is the kitchen sink, hes referencing that he is unique)

Clearly, the rest of the song is motivating. A pick me up for other 'kitchen sinks.'

'leave me alone, Don't leave me alone'

When youre in a spot like this you might confuse yourself and say you don't need people. But youre really just screaming for people to see you and appreciate you.

Find purpose in whatever you can. Don't worry whether youre good or bad at it, just do it, and like he says, 'you'll see purpose start to surface'

Thats my take anyhow.

My Interpretation

@fr0st2k its me