I'm not a doctor, so I can't tell you that what you're experiencing is definitely GERD related, but I can say that many GERD sufferers have the feeling of something stuck in their throat, which leads to the feeling that it's difficult to breathe. Many have actually been to the ER due to those symptoms. Actually, anxiety is another symptom that strikes many GERD sufferers.
Have you had any testing to determine whether or not you're experiencing reflux? It would be well worth the effort to make an appointment with a trusted primary care doctor, or GI doc, if you don't need a referral.
You're in the right place! I'm sure others will be by to post responses.
Take care, and good luck!