Thorn - any suggestions?

[Grain]

This song is a lot more open-ended than the other songs I've translated. I asked some Japanese people, and apparently they had no idea what the grammar is supposed to be; you just have to fill in the blanks. It makes me nervous, but I don't wanna just do love songs forever. Every single line could be translated differently, so this time I'm asking for comments/suggestions on the entire song. I think I connected all the verbs to their correct nouns, but I'm not 100% sure. Thankfully the song's not too long. I'm not sure how I can elegantly yet accurately translate 育てた刺. The last stanza is English, so I just left it that way.

宇宙(そら)を 夢見ていた あの頃
いま 心 壊れた破片(かけら)の中 零れ
落ちてく
Back in those days, I would just dream and dream of the sky
And now, I feel it spilling over into the broken fragments
Of my mind

いつからだろう 心は凍えていた 震えていた
どこからだろう 瞳には何も映らない 哀しみさえ
彷徨った あの空に
When did this start happening? My heart would ice up and shiver and shiver
Where did this begin? Even the sadness that my eyes don't reflect at all
Got lost wandering around in that sky

鳥は 何処の空を 飛んでる?
あの 風は 囁かないのだろう 二度と
此処には
Where are the birds soaring through the sky?
Maybe that breeze will never whisper again
Not here, anyway

目覚めてみれば 心ない言葉たち 傷ついてく
If I try to wake up, I end up getting hurt by callous remarks

眠っていれば 焦がれる炎 焼き尽くして 優しさにも
気付かない フリをして
If I stay asleep, the flames of desire dwindle down to nothing—as well as my kindness
All while I pretend not to notice

独りぼっちで 蒼い夜の中にも 目覚めている
心の中で 育てた棘(とげ)が痛みの中 失われた
想い出の 血を流す
Utterly alone, even in the middle of the pale night, I lie awake
The thorn I cultivated, amidst all the pain in my mind, has been lost
And it makes my memories bleed

The pain will disappear, if only I could pull this thorn out-
But the thorn that's growing in my mind
makes me deny my feelings, makes me refuse love-
and it bleeds inside of my memories.
Leaves me with a scar in my heart.