I think you are:
See me for I am held in the attraction
Stars are in space, which is what is spelled in the first letter of each line
Protection from your home I've given
When young children are troubled, they often wish upon stars. This is especially true if there are issues at home.
Adding resource should you ever reach
If we ever reach another star, we'll gain a lot of natural resources (hydrogen, helium, whatever metals make up that solar system).
Come not closer, I am possessed of breach
Breach is defined as a broken, ruptured, or torn condition or area. Could this refer to a sunspot?
Entwined in myself, I am the right size
Is this referring to a binary star system?
I am many but one name
There are many stars, but they're all just called stars.
Hint: "Serpentine guards like garter."
Here is the main reason I think it is a star. Each line in your clue ends in "ter", and when I think of serpentine, I think of an s. So "ster" or star.