Restlessness, High pulse. Acid reflux?

Whenever I do some work or walk in the house hastily, I would be restless being not able to breathe properly and I would feel my heart racing (high pulse). Sometimes even when I walk fast in the house this problem occurs. 5 months ago I took blood test, echo, ECG, chest X-ray for cardiac tests. Everything was normal except during ECG test my pulse was high. Otherwise everything was normal. I was not able to sleep for more than 7 months. Moreover,I had acid reflux for some time, I would feel breathless after meals sometimes. I thought that high pulse and restlessness is due to acid reflux and didn't concern with cardiac problems. So, what is the cause of the problem? Is it due to heart because of lack of sleep or is it due to acid reflux? Please help doctors 🙏🙏. Thank you