Hi Sunny ,
Do you drink enough water ?
Caffeine , dehydrates you , so if you enjoy coffee , have a glass of water with it.
I have anxiety issues and I understand tachycardia , not fun at all.
Here is the weird thing , if I can`t sleep at night , sometimes I will have a cup of coffee , and about a half hour later I am out like a light .

really .
For some strange reason caffeine makes be sleepy, ok so who's crazy !!
Take care
Keyplayer
