Hi. Noted your history of fibromyalgia and inflammatory arthritis. The reason for the headache can be vascular as it has caused you have also got numbness in the areas you mentioned. Twitching of the thumb and tickly feeling in the ear can be due to various reason as below: - Tiredness and weakness as you already have it. - stress and anxiety. -Overwork - Electrolyte imbalance. I would advise you to get a clinical evaluation, actual physical examination and investigations of the blood for electrolytes and other relevant tests as may be needed under the order of your Doctor and also to get a prescription for proper medications.