I see, this is because you work for a medical practice, not because you're a patient. I hadn't thought about that. Here's one more idea...
With your employer's okay - (no sense in losing your job) - you might be able to promote this online forum by printing up 3 1/2" x 8 1/2" fliers on card stock, but without any personal contact information, for distribution where ever their are public bulletin boards in your community. Business sized cards could work too.
My plan, whether I do or don't start a local LCHF support group this fall is to do exactly that, but to include contact info for all the local diabetes groups too, with their permission of course. I figure if I can't start a group, I can at least get information out about all of our local diabetes support groups including this online forum (because it's my favorite diabetes forum.