Hi, of the things you mention I think acupuncture is probably most effective for this kind of problem. I would be inclined to keep focusing on the problem with your back you already know about. Have you seen a chiropractor? I wouldn’t be surprised if the problem in your face was a direct link. You could consider iridologist for diagnosis too. Re the gelsemium it tends to treat pain more than stiffness, maybe worth a try but it of course isn’t helping you get to the root cause but may offer some relief?
All the best