Can someone help with these sentences

First of all I wanna mention that I'm a beginner at Japanese. I really wanted to translate some songs so I can understand what they are saying (I couldn't find the translation anywhere).
So I'd like if someone could correct my translation for some of the lyrics and help me with the sentences I don't know.
I probably made lots of mistakes >.<


闇に咲いて 舞い落ちる雪の華 ひとひら
Flakes of snow bloom and flutter down in the darkness
その間(はざま)に
とぐろ巻く銀(しろがね)の
(I know that その間に means "meanwhile/during that time", but I can't make the connection with とぐろ巻く銀(しろがね)の)
はらはらと頬つたう哀しみを
???
神々の酒となす涙壺(なみだつぼ)
A pot of tears change into the Sake of Gods


その水面(みなも)が映すは
儚き愛しき人微笑み浮かべて
The surface of the water reflects the smile of my fickle and dear person


憂いて鼓(つつみ)打たぬ
Beating the hand drum with anxiety
その胸鳴らすために
In order to ring to my chest


はじめはそう思っていたいつしかこの心
At first that's what I thought, that this unawares heart
お前のことしか見えなくなってた戻れない
(I know it says something about "becoming unable to see" and "can't return")


簡単で難解な心理隠し守るぞ神使
???

You should at least have mentioned that you quoted some parts of lyrics from two different songs and provided us the entire lyrics. I thought, for instance, 儚き愛しき人微笑み浮かべて was directly connected to 憂いて鼓(つつみ)打たぬ since I didn't know you skipped two lines between them, which doesn't make much sense.

Firstly, as for ひとしずく;

ひとひら is singular.
その間に can be used for "spatial", not only "temporal".
はらはらと頬つたう哀しみを神々の酒となす modifies 涙壺. That's a noun phrase, not a sentence.

打たぬ is negative.
その胸 doesn't refer to "my chest".
(FYI, くちびる濡らす modifies 一滴, and 一滴 is the subject of 沈みゆく.)