Chiari, fibro, etc, high potassium, platelets 509. Acth 3 range7-63.3endo concerned TSH 3.8.What does all this mean? &horrible pain all over. How sick am I

Fibromylagia. Are you diagnosed with fibromyalgia. If so you need to get on fibromyalgia therapy - focus on sleep, exercise and control of stress and then medications. You are not getting treated for your fibromyalgia.
Hard to say. Visit with endocrinologist and neurosurgeon who is knowledgable about chiari.