Help with anxiety attacks

I need some advice. I have been having anxiety attacks for about a month now. The first one happened when I was driving (I got home safely though). They are triggered by the smell of heating in vehicles, particularly my parents car, which is the one I was driving. I think it is also made worse by knowing I can't get out, especially on the motorway.

Now, I can avoid taking the car quite well, but every car ride has been a nightmare. The last one ended with my mum driving and me breathing into a plastic baggy for 20 minutes to stop hyperventilating.

But in a week I'm going to see a theatre show with my parents and my sibling, which should be fun, but I'm already dreading it because I know we will take the car. My father doesn't know about the attacks, because he doesn't understand that sort of thing. I absolutely do not want to have an attack in the car and have him tell me to stop acting like a child and to stop crying, ruining our family night.

So, let's say I'm in the car, feeling anxious but doing alright, how do I prevent it building towards an attack? I have tried many breathing techniques but they don't seem to work because I am triggered by smell. I have tried distracting myself or listening to music, but nothing has helped. Fresh air helps a little, but the windows in the back don't open. My only strategy to get out of the suffocating phase of the attack is by opening the window, so it also frightens me that I won't be able to do that.

At this point I'm honestly considering making up an excuse and taking the bus. Please help.

P.s. I'm seeing a doctor next week too, but the day after the show...