Is it anxiety or my heart

I keep having this lethargic feeling at random I feel breathless find it hard to speak and am unable to move I can feel my heart beating out my chest and the only thing that seems to help is laying elevated or sitting still for a long period of time now I've stated feeling numbing and a pin and needle sensation in my hands is this all linked or am I worrying about nothing if this sound familiar ure advice and experience would be appreciated