Bathing into Epsom Salt is not only granting your body the magnesium it needs, but also the sulfur - Skin pores will let them in and you wont get to poop it out like when you swallow it. I have had the same experience - though I am using MSM supplements and magnesium supplements orally (just the tiny bit so it does not cause diarrhea) and no longer the bath like I used to.
Like you, I am close to being diabetic and a fast sets me on the right track on and on. I keep taking magnesium (chloride mag:2 drops a day ) when I do not have time to fix a green juice. Magnesium deficiency was the issue.