Low Blood Pressure

I’ve been having low blood pressure that causes me to be extremely cold, that I have to wear a jacket when it’s 73-75 inside. My blood pressure is usually 110/70, but it’s been dipping down to 80/50. The lowest it’s been is 83/45. I’ve been experiencing lightheadedness, shortness of breath on exertion, face is sticky, feeling cold and fatigue.

But - I can experience these symptoms (except feeling cold and sticky face.) even though my blood pressure is normal. 

I want to ask another question. Why does my heart sound like it’s adding an extra beat after the second beat? It’s very close together, but it sounds like a flip flop.