Layla, I think you are right to question the whole idea of bringing your dog here.
I have three working gun dogs back home in UK, and whilst I went through the same turmoil as you to come to my decision, I know, wholeheartedly that it was the right one.
All dogs and but more especially those from working lines need mental stimulation as much as (and often more than) physical excersise. That would indeed be a challenge, although not impossible to do at home here. But your pointer will want to hunt through the undergrowth as he does back home and take in all the scents that stimulate his mind. I'm not sure that you would really want to (or be able to) do that here.
I don't mean to be rude Leanne but I'm afraid dogs don't pine for us, contrary to popular belief! They might be unsettled for 24 hours or so, but as long as they are in a good loving and caring home they do not think about us AT ALL. Dogs live for the here and now. They are far more selfish in this respect than we are!
I don't know how long you expect to be here but you may be lucky and find a "temporary" loving home for her even for a couple of years.
My three are cared for by different friends. One lives with a close girlfriend who doesn't feel able to commit to a dog for 15 years, but adores her; another lives with a young family and two other dogs simply because they wanted to have her so much; and the third, who was a puppy of three months when I left, lives with 8 others of her kind, in a working / training kennel where we pay a nominal amount for her "board and lodgings".
Whenever we are home in UK, they all move back in for that period, which works well and gives the friends a break. We pay for their food, vets bills, expenses etc and thankfully everybody seems very happy with the arrangement.
It is us, not the dogs, who suffer the separation. Their minds do not work the same way, I'm afraid (but glad!) Sure they're exstatic to see you on your return and slot back into your life as though they were never away, but the same applies when they are returned to their temporary homes.
To compensate for your pining why not volunteer to do dog walking at the SPCA here?
There are so many needy dogs there who would love your attention.