More.
Todd, you're absolutely right when you say "…In reality there is really no other word that fits the person or persons in our lives that walk through this journey with us."
I did a quick websearch of word synonym sites (Roget's Thesaurus type sites) and, by golly, I found few if any synonyms for the word "caregiver."
Like it or not, it seems to be one of those words that stands pretty much alone in conveying its idea.
I did find a synonym site that did offer a few alternatives for it, but none of them captured the meaning, sense, and even the emotion, that the word "caregiver" itself brings:
www.thesaurus.com/browse/caregiver(BTW, one of those alternatives, "lady of the lamp," struck me as having a certain charm to it, like someone coming in the night, bearing a nightlight, coming to one's aid, but I guess it does sound a bit too much like something out of a Jane Austen novel or something <grin>).