Yes, I agree with the above thread. It would be very helpful to get more contact with a group or more visits-at least weekly with your shrink.
Believe it or not, many Alanon and AA members have a history of trauma. Even though their trauma is not exactly like yours, it is trauma. i found out that I was not Alone. And being able to be with others, I eventually noticed that groups helped me not feel so panicked. Dimly Google AA and Alanon meetings; I recommend that you go to a few different meetings to find a group of people that you relax with.
It took me time to gain conforms with these groups, and be grateful that they understood trauma. My experience is that AA members more readily relate to 'hitting a bottom' like you describe. Going up to people after the meeting, and having a personal conversation was the best part; go to coffee with them.
Your profession, firefighting, due to the level of focus on surviving dangerous circumstances and saving lives, may not understand trauma, and the level of support and that it takes to heal; everyone heals on their own individual schedule. And there comes a point when a person can't just 'shut out' the trauma thoughts-suicdal, and related depression.
I support you to recognize your symptoms are showing that you are deserving of more help. Most people need more help to get through trauma. You are not alone, here.