I really thought this was great. The title really catches the eye, and I like how simple the entire poem is, you don't try to push very strong imagery, which gives it a more light, lazy kind of feel.
I really love how the entire poem tells about your experience of something all of us feel at one time or another, the feeling of losing so many great ideas and lines to, just not feeling like it. I loved this
You were trying to describe writer's block in the first stanza by merely telling what is happening... "muscles to move..." - Actually when a poet awakens, he/she does not care about muscles moving. There are much more significant things to worry about. Also, try and be creative with the topic you have. Writer's block... see any symbolisms? Block... Walls... imagine a person locked inside a windowless room, as if never to experience life again. Couldn't you follow a metaphor bigger than an image of a person wanting to move their hands to write?
You can do better than that.
Also, deep thoughts reaching the bottom of an ocean is such old figure, this metaphor also was not used to push through by you.
What I mean is, if you want to go along with this metaphor, and connect it with writer's block. Why not put the speaker "literally" at the bottom of the ocean and work your metaphor there?
As if the speaker loses oxygen underneath and the valuable thoughts unwritten gets lost in sea?
The following lines are plain. Like a rushed email letter.