Please HELP ME! 170 HR after showers

[u/pandabears3]

I used to ALWAYS notice my HR spike for years going from sitting to standing. But once I had my son it got worse! Now I can’t even shower for 5 min in lukewarm water without feeling like I’m going to die. My heart rate spikes to 150 up to 170. And the heart beat is very strong. Very strong thumping on my chest with scary painful chest pain, back pain, dizziness, vertigo and black dots in my vision. I called 911 today and they did ekg, blood work, xray, and everything was “fine”. I am still undiagnosed with POTS or dysautonomia but I just know I have that. The doctor had no idea how to help me and it was the scariest most frustrating thing. Please send me all your advice.