I'm so sorry to hear that, you must be really sick of panic attacks. I suffered from them for a while after a series of traumatic events.
Doctors were useless and the only thing that helped me was cognitive behavioural therapy. This actually takes apart your behaviour and teaches you what is happening when you have a panic attack and ways to recognise that one is about to occur- giving you some control over the situation and less anxiety about one "suddenly" starting.
For instance the process of a panic attack beginning starts long before you actually feel the shakes/cloudy head/sweaty palms etc. Your brain is processing faster and faster, your heart rate accelerates. My CBT therapist taught me to:
Stop the panic. Slow things down when the panicky feelings started. Think logically to myself what exactly I was panicking about - "I might be sick" would be answered with "okay, but what's the worst that would happen, I would be embarrassed but I would still survive, I'd be okay and I've never actually been sick with one before".
It's also really important to learn how to breathe properly. If you can slow your breathing down you can slow your heart down and feel calmer.
Do you see what I mean? It was the only thing that worked for me, betablockers didn't help and I really didn't want to take Valium having seen friends really not happy on it.
Your doctor should be able to refer you for treatment. Can you ask to see another doctor? I generally just say I need an appt that day and don't care who I see if I don't want to see a particular doctor and then just keep saying I can't do that time until I get another doctor.
I actually went private for my CBT in the end, which I couldn't really afford at the time but long term it was the best money I ever spent - it treated the cause not just the symptoms.
Big hugs to you though, panic attacks can be crippling. I hated them and used to get them loads at really crowded stations/London Underground. I thought they would never end but they did.