hi im a 50 year old female lately ive been going to sleep and waking up feeling as if my throat is closing up i could hardly breath feels like im breathing through a small straw the harder i try to breath the tighter my throut feels but as i sit up and calm myself down and breath slower it starts to get better can you please tell me if i need to get emediate attention it only happens when im asleep it has frighten me very much