Feeling like I can’t breathe but I’m getting enough air

I’m 16 and have severe health anxiety. One of my biggest fears is cancer, as my dad died from it last year. I was sick a couple months ago and I’m still coughing up gunk but it’s been getting harder and harder to cough up anything, but I’m still having trouble breathing. Doctor says I’m fine and my blood oxygen is fine too. Can anxiety make you feel this way? Usually I have shortness of breath but this feels like my lungs are heavy and my throat is tight. I’ve never felt it before and it makes me nervous.