As for the purpose of chanting Buddha, from what you said, you made a fundamental mistake. Can you read Buddha without getting sick? That Buddhist won't die. How can he live in bliss? Hehe, just kidding. You must have the right motivation to read Buddha. This information can be found on the Internet. You can search.
I'm a doctor, and sinus tachycardia is not a big problem. Not that you are so nervous! Meditation to become a Buddha is just a good way to treat it! Ordinary people will appear briefly when they are nervous or excited. On the contrary, the more sensitive their nerves are, the more likely they are to attack.
I suggest you consider whether the mentality of chanting Buddha is correct. Don't experiment with chanting Buddha. Doubt is a serious problem in chanting Buddha! !
Read Buddha in another way, relax your body and mind, and you will get better slowly.