Hi Apple, and welcome aboard.

Train crash... wow, that would have been quite scary and traumatic, especially at night and in a location unbeknown to you, which just sends every sense into overload and uncertainty. The really great news is that you got counselling, and fought through many of your issues, which is really outstanding to hear. Congratulations on being very proactive in that aspect.

Anxiety! Anxiety is caused by exactly what you have described yourself doing. The problem is, is that your obviously working out that you need to tell yourself what reality is vs. what you have made up and assumed within your own mind, but your not believing it, hence the mass anxiety is still current.

This is all about thinking styles, patterns and your thought perceptions. If you haven't already found this piece about unhelpful thinking styles, then you probably should read it, as it is directly related to what your experiencing.

By the sound of things, you pretty much know what you are doing wrong, but just can't stop yourself doing it. So denial isn't an issue, which is already a great milestone for you. Basically all you can do is arm yourself with as much information and education on anxiety you possibly can, constantly read content, even re-read until your 100% that you know it, then just work on applying it. A counsellor may of already told you that most of the problem lay within your mind now, and that only you can fix you from this point on! Information and education really is the key, then actually applying that information and self-education is the hard part, and that takes time, so don't beat yourself up about it.

You have suffered a significant trauma from a life threatening accident, and only time with education can now heal you from your last concerns and problems. You will never actually get over what happened, but more come to terms with it, that it has happened and you can't change it, and now move forward with life and slowly learn to control the symptoms, being anxiety for you, more specifically panick attacks. I have posted some possibly useful resources and information below for you to consider, and hope it helps you.