Thread: hope you can correct me because i think that i have some mistakes here

Hello !
I want to say " as long as i am alive , i won't alllow you to feel sad even for one second" in Russian
so here is my attempt to translate " до тех пор я живой, я не буду разрешать что ты грустно чувствуешь не даже для одной секунд "
Thanks , Guys

Пока я жив (it's a set phrase), я ни на секунду не допущу того, чтобы ты грустила.

That's my version, other versions are possible

as long as i am alive , i won't alllow you to feel sad even for one second

Almost literally: Пока я жив, я не позволю тебе загрустить даже на одну секунду.

Пока я жив, не дам тебе грустить ни секунды.

Russian normally can use much less words for the same idea than English and it is a better style in Russian to avoid junk words. The words are longer in average though.