I've tried most of the sugested techniques
Nothing works
I feel like.............there is SOMETHING I should do, that I am not doing

Maybe you need a different therapist.

Have you tried any meds? Panic & fear is a result of;

"fight or flight" mode in response to something you think is a threat. As your body tries to take in more oxygen your breathing quickens. Your body also releases hormones, such as adrenaline, causing your heart to beat faster and your muscles to tense up.

I have taken beta blockers, very effective in controlling panic attacks, and paroxetine an SSRI for anxiety & OCD together with much self help (I couldn't afford a therapist) positive thinking, mantras repeated many times a day 'I am enough, I am always enough' and I am (almost) normal now, apart from an occasional bad day.