CANT breathe

Hello ever since I started going to therapy last year and became fully aware of my terrible anxiety it’s been hard for me to breathe in certain situations like when I am in class I get so nervous that I don’t breathe. Or when I am near a guy that I am sort of interested in but it also happens sometimes outside of “social situations” like when I climb a couple of stairs it’s hard for me to breathe or it just randomly occurs at times. I wanted to know if anyone experiences anything like this and what kind of medicine I can use or what it’s called before I talk to my doctor or therapist!