I am—yet what I am none cares or knows;
My friends forsake me like a memory lost:
I am the self-consumer of my woes—
They rise and vanish in oblivious host,
Like shadows in love's frenzied stifled throes
And yet I am, and live—like vapours tossed
Into the nothingness of scorn and noise,
Into the living sea of waking dreams,
Where there is neither sense of life or joys,
Taken literally, this line says that despite all of the previous woes (“I am the self-consumer of my woes”) what the poet shall cling to is the very fact that he lives even though this life is like “vapours tossed / Into the nothingness of scorn and noise.” What the poet claims is the proto-existentialist claim: that to live and to continue living is more significant than any earthly (ergo temporary) woe. Though the torment is real, to be and to live is more significant. 
 This line could also claim that the torment felt is real; the use of the word ‘yet’ solidifies its (the torments') effects despite it not being recognized by others. The thinness of its existence further emphasised by the use of the word ‘vapour’ – here one moment, gone the next. 
 This could be an allusion to James 4:14: “…you do not know what will happen tomorrow. For what is your life? It is even a vapour that appears for a little time and then vanishes away.”
I Am