Waking up with cough.. heart rate 160, nausea & near fainting

i have been having some scary episodes and I’m trying to understand what’s going on. Sometimes I wake up from sleep with a light cough, or a weird feeling in my throat that makes me cough. Right after that, my heart rate suddenly jumps to around 150–160 bpm. I also feel a strong heat in my body, nausea, and like I might faint, and I get an urgent need to go to the bathroom multiple times. The high heart rate lasts about 30 minutes then slowly comes down. I was recently told I might have POTS, but these episodes feel very sudden and intense, especially from sleep. Has anyone experienced something like this? Especially the cough or throat feeling triggering a strong heart rate spike?