HI, thanks for using healthcare magic The most common reasons for headaches are : migraines, tension headache, sinus headaches, cluster headache. Migraine headaches can be brought on by stress , some foods, sleep deprivation. They are typically on one side, throbbing, severe and last at least 4 hrs. They also affect the ability to do routine activities and are associated with nausea and worsening of the headache with light and noise. Tension headaches are usually a tight or heavy type of headache. Not associated with nausea or worsening with noise or light. They are usually at the front or back of the head. These headaches are not worse by normal activities like migraines. Sinus headaches would occur in persons with a history of sinus problems. It is possible that stress or anxiety can bring on a headache either tension or migraine. If it fits the criteria for migraine you can consider speaking to your doctor because there are migraine specific medication that can be used. In terms of the persistent feeling of fullness in the stomach this can be related to different conditions such as GERD, constipation, side effect of medication, it may also be related to your thyroid disease. I hope this helps