Is difficulty breathing a common symptom of anxiety attcks?

Yes: This is common in a panic attack. In panic, all muscles in the body tense, so the chest muscles work against the lungs trying to inflate. Also, adrenaline makes your breathing rapid & shallow for efficient fight or flight. Best immediate action is fully exhale all the air, your diaphragm reflex will give you a better breath. Find a therapist who does exposure based therapy for panic disorder.