It's probably not "late to erase the distortion of the unstoppable chest" :-)
- It's 止まらない, not 止まれない.
- I think it's the 歪 which is 止まらない. In other words, 止まらない modifies the phrase 胸の歪.
- 〜ておくれよ is probably 〜てくれよ with the honorific お- added to くれる.
Here we have an imperative form of 〜てくれる, so it seems the speaker is asking the listener to do something for them. So the listener is the (implicit) subject of 消す, but with 〜てくれる there's no reason to put it explicitly into the sentence.
I think that in both requests, the speaker is talking to Amethyst:
- 止まらない胸の歪を消しておくれよ アメジスト
- 救っておくれよ アメジスト
I can't come up with a literal translation that sounds right to me, so I'm going to try a relatively free translation, replacing 歪 with "pain" and 消す with "take away":
Take away this endless pain in my heart, Amethyst
Amethyst is the listener, referred to elsewhere in the song as 君.
This translation isn't perfect—maybe someone could comment if they can think of a way to improve it, particularly how to express 胸の歪. "Pain" isn't quite right for 歪, but I don't think the literal "distortion" is totally appropriate, either. Some dictionaries give "stress" or "strain" as possible choices for the more psychological meaning, like in 心の歪.
But in any case, I think this should get you a little closer to the author's intended meaning :-)