Welcome to the site!
Could the asthma be making your chest feel tight and the anxiety aggrivating the asthma? I do understand panic attacks tho, I get them too unfortunately and they royally suck. I went to an anxiety specialist and she gave me "coping" skills such as the slow abdominal breathing and changing the negative thoughts and tracking them and then looking back and realizing it was OK. Can you find or have your GP help you find a therapist who could help you to maintain the anxiety rather than the other way around? It really does help alot to have someone understand, believe you and be able to give you tools to help yourself. I hope this helps some.
\"As soon as you trust yourself,you will know how to live.\"
Johann Wolfgang von Goethe
\"Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight.\"
Benjamin Franklin