It's been over two months now, and I've been having trouble breathing whenever I laugh or talk. I often feel out of breath. Ive already had an X-ray and a cardiac check, and both came back normal. What could be causing this?

It sounds like you may be experiencing a form of anxiety or stress-related breathing difficulty, especially since both your X-ray and cardiac check are normal. It could also be related to muscle tension in the chest or diaphragm. I recommend consulting a respiratory specialist or considering breathing exercises to help manage this.