@user1464187087 kindly you needed to leave that job.
What you got calls about was highly distressing, no question, but what you got calls about, other people go out and see that face to face. Police, ambulances, fire services. If they were missing a lot of time because of the trauma they experienced then it would not be possible to provide the services any longer. In my experience of engagement with front line staff when that time comes, when the level of trauma affects them to the degree they cannot do the role any longer then they have to redeploy and get different roles.
These types of roles including the one you did need people who can deal with that level of trauma. It is not a weakness to be affected by trauma but it is not appropriate to stay in a job where you are experiencing ongoing trauma to the degree that you cannot fulfill the responsibilities of the role.
Why didn’t you consider changing roles when it was clearly impacting you so badly? Why did you stay when doing the role had become untenable for you?
You sound like a conscientious and dedicated staff member but you had a blind spot around when it came your time to leave a role that was harming you psychologically. Now you are beating yourself up about being let go which is not healthy for you either.
By all means go to a tribunal if you feel that will help you, I personally don’t believe it will because it will keep you stuck, but I would focus on reframing the fact that you did a really good job until it became untenable for you to keep working there, you probably should have left sooner than you did and now it is time to start something new.