Hi there!

First of all, you are not alone. Many of us on here suffer the exact same thing you just described. Anxiety and panic attacks are horrible and I suffer daily from these things too.
I recommend to not let it get too bad early on, so you've noticed that it has started getting worse. The worst thing you can do is avoid going to shops and getting in the car etc. because you're convincing yourself there is a real threat when really, these panic attacks you have experienced are not triggered by any real threat.
So my biggest piece of advice is to not avoid things and try to live your life as normal as you can. I went through a stage of avoidance and it was the worst thing I did and took a lot of effort to try to do things normal people would do.

Keep seeing your therapist and do what you're told to do, good job on cbt therapy!

Never feel like an idiot or stupid or embarrassed from panicking in public, you'd be surprised how many people would know how you are feeling.

I also recommend doing as much research on panic attacks and anxiety as possible. The more you know and learn the better you are able to understand what is happening to your body when you are panicking... Such as understanding WHY you have tingling or feeling hot etc. Knowing why my body reacts that way helps me get out of the panic attack.

If you YouTube search: Zoella panic attacks... You may find that video helpful as she explain panic attacks in depth and from the point of view of someone that suffers from anxiety and panic attacks.

Hang in there, I onow exactly how you feel!

xxx