I interpret
I bring you life as in 2 bound circle-like shapes!
as
DNA, chromosomes, or genes - the double helix. Since they are made of proteins, you could also try proteins or molecules here, except that the OP has said molecules is not the intended answer.
How to make it fit the other clues?
You need me. You need me in many ways. Yet, I'm slowly losing my family.
Sure, we need DNA to keep making new blood, bones, skin etc as long as we live. As your ancestors die, your genes or DNA lose some of their family.
You can count on me as you always did!
Same as you need me, really
The sound of an explosion, transferred to the orange land.
I have nothing here. Perhaps "the orange land" is the Netherlands, who use orange as a symbol for sports teams etc, or Spain, where oranges grow. I can't see a way to have bang, boom, or other explosion sounds somehow "transfer" to another country so this clue mystifies me.
I can stop the darkness!
Some species have genes for bioluminescence
If you want, I can even stop the bitter cold!
And some for antifreeze-like properties
I bring you life as in 2 bound circle-like shapes!
This is really the crucial clue for me as I said above
Yet, I keep losing my family. We are torn apart by whom who need us most.
The first sentence is a repeat. The second might refer to the fact that each parent passes on only half their DNA to the offspring. It's "torn apart" to pass on half