Panic attacks are horrible and they are not as accepted or understood as they should be. People just don't seem to understand how truly terrible and debilitating they are, so I can see where you're coming from in not telling your professionals. For me, I found it useful to carry things around with me that helped me feel safe and calm such as a notebook with positive messages from friends, water, Rescue remedy drops (don't know if they work but I don't care, they did for me!), mints because they clearly your airways... etc.. It's important to have something close to you that will help you calm down.
Perhaps you could have a think about what makes you have these panic attacks. Note down when you have them so that you can notice a pattern. That way, you might be able to guard against them a little bit more.
I have a few links that might be of use to you:
Coping with panic attacks workbook, Panic Attacks Online Self Help Course and Five Ways to Calm Down. These might be worth looking through. It may also be useful for you to look into mindfulness as that can help you become more aware of your surroundings and what you're doing. For example, when you have a panic attack you notice things by going through the five senses; what you hear, see, feel, taste, smell... Breathing techniques can also be useful such as breathing in colours or counting/repeating the numbers twice.
What is it about these 'so-called professionals' that means you can't talk to them? What makes you think they're against you?