Sounds like you have an awesome dog.
"I feel like I cannot control the situation beyond my own dog." This is true for everyone, but we can control our reaction to the situation.
I used to have panic attacks where I couldn't breathe. I suggest you develop strategies. Have you tried distracting yourself by reciting memorized poetry, multiplication tables or math formulas, favourite recipes or songs, talking to your 5 year old? Jaw relaxation exercises may help towards preventing you tensing up. Develop an attitude of I choose to be in control and I'm improving with my coping skills, rather than letting anxiety overwhelm and define who you are. See anxiety as something you are gaining control over, not anxiety controlling you. Discipline yourself to smile, smiling is your face telling your brain you are happy. Discipline and train yourself, it takes time but you will see progress.