Throughout the poem you used the word 'that' too much. It kills the mood when stressing a word.
"The sun it does down, to leave us alone" You mean goes down. Atone
"To cry on inside and die on the surface." it's either: to cry on the inside or cry inside.
The last stanza was definitely the best.
In whole, you need to edit your poetry.

That was really good, I think you did really well with the poem structure and everything :)

this is a way wicked poem!>.< keep it up, it was really touching though, honestly