When I lay down at night and get nice and relaxed and almost asleep my stomach does this weird flop thing or almost like when ur stomach drops.... then I feel very strange and can taste metal in my mouth. It's a very scary feeling. This happens several times a night and has been going on for about a month now. I am fine during the day except maybe a little fatigue. I am a 45 year old female.... 5"6" and 170 pounds. No routine meds just ibuprofen as needed. This is making me crazy.