caonaí is a person on there own, uaigneach is very lonely
Taking just this snippet, I'm not sure I'll get the poets intention.
I would understand it to mean
I am a very lonely, solitary person,
nach mór go bhfeicim an lá is ambiguous, it could either mean I won't survive until the dawn, or I'm longing for the dawn.
Reading the poem which I found here http://www.poets.org/poems/poems.cfm?prmID=1154
I think the second is probably more correct.