DISCLAIMER: I suggest you consider vaping zero nicotine juice, but if that doesn't work for you...
I feel like without vaping at least I'll return to cigs, but my gf still sees vaping as a form of "poison" entering me and doesn't know how long vaping as a habit would last
It sounds as if you girlfriend has an over-inflated sense of concern regarding nicotine.
That probably means that she has fallen prey to years and years of brainwashing, and needs an education.
Nicotine is a stimulant with effects similar to caffeine.
Ask her what it is about nicotine that makes her so concerned.
If her only objections is that it is a "poison" then here is how you handle that...
Pretty much any substance on earth, if taken in the right dose, will kill you.
If you drink too much water, or eat too much salt, you will most certainly die.
In the amounts we ingest, nicotine will not kill you.
It won't even come close.
You might also want to read this...
Nicotine Effects
Nicotine is being considered as a therapeutic agent to treat such conditions as attention deficit disorder, Alzheimer's Disease, Parkinson's Disease, Tourette syndrome, sleep apnea, obesity, ulcerative colitis, and inflammatory skin disorders. [1]
Nicotine has the following benefits:
Relieves depression [2]
Reduces anxiety [3]
Improves ability to concentrate and long term memory [4]
Protects against developing high blood pressure [5, 6]
Protects against weight gain [7]
Protects against developing Parkinson's Disease [8]
I'm not trying to say that nicotine is wonderful and everyone should have some.
But I am trying to say that nicotine isn't the horrible demon that society has been led to believe.