fast heartbeat

Hi everyone again! I just recently had COVID-19 just over a week ago and I have to say, I thought it would be much much worse, given my existing health problems too. I only had symptoms for one day, then they basically subsided and I appeared to be asymptomatic. The only symptoms I had though...

When I lie down, my heartbeat gets hard and fast after a while. My breathing also automatically speeds up. I feel scared and a little confused. The noises in my ears and head noises are getting louder. That makes me impossible to rest because it makes me crazy. I sit down again and the symptoms...