My Throat Feels Like Its Somewhat Closed Up. I Coughed

My throat feels like its somewhat closed up. I coughed hard several times in bed fri a m. Woke up later cause i couldnt breath. Finally after 15 min or so i kept clearing my throat and finally caught my breath. Could it be my thyroid swollen? MY DOC TOLD ME6 MO AGO I HAVE A HYPOACTIVE , started on levothyroxin but couldnt take it cause it made my throat feel odd. Im scared to lay down now. Can you help with sugestions? Thank you , madk.