Comes and Goes

this feeling comes and goes when it's gone I feel good while it's here feelings vary though sometimes it seems to always be here, like it belongs at times I shake, feel the need for relief, occassionally I crave though I try not to give in, which is for the most part sucessful, depression always comes with it how long this time? this question I ask myself though I know we do not know the answer we are scared, scared that one day it may not leave what will become of us if this were to happen?