Weird breathing issues?

Been taking 150 mg XL for three weeks and the only real side effect that has stayed with me is breathing issues.

My heart rate has increased, so that might have something to do with it.

It comes and goes — it’s like I can’t get a full breath and I kinda struggle to breathe and it effects being able to talk or laugh, like my voice just suddenly dies.

I’m coughing a lot more too.

Anyone else experience this when first starting and did it improve?