The cause for the breathing issue is certainly a knot in the top of your back, most often it's the right side.

Don't let them sell you a false diagnosis and fill you up with drugs that you do not need and will only cause other health issues.

Get yourself a good massage and start working out, change your back and nek posture by sitting correctly.

The knot also gives other symptoms which will make your life miserable, you will feel so much better once you follow the advice i gave you all.

You probably also need to visit an osteopath to get straightened out.
You'll notice what i mean once you go.

Good luck!