So lots of comments here are suggesting that you have a medical issue, I'm not going to go that far without knowing anything about you, but that is a very high

So lots of comments here are suggesting that you have a medical issue, I'm not going to go that far without knowing anything about you, but that is a very high breath rate. You may want to focus on where you are breathing in your body. I have a very slow breath rate and super slow hear-rate, so 4 seconds is painfully fast for me. I'm about 8-10 seconds in or out and a comfortable 6 or so seconds rest between breaths. To breath quickly, I have to focus on breathing only in my upper chest. You may have been trained to do this over-time, and feel very normal doing it. Watch a child breathing, and you'll see they breath deeply into their belly. This is the natural breathe you want to aim for. If you've been breathing into your chest for ever, your lower lungs are likely going too be tight, and it will be very difficult for you to expand and breathe into them. But it's worth trying. When you lie down, try relaxing and try to relax your stomach and let it rise and fall with each breath. It takes re-training your diaphragm. Where I do agree with the other comments here is that you likely should decrease your breath rate as it is better for you, as long as there is a good reason for you to be breathing as quickly as you currently are.