I think I did ok

I was leaving work today and I passed a man who was very quiet and seemed to be shivering. The weather had been cold but now it was warmer. I wondered why he was shivering. I went back and talked to him. (engaged in conversation) I simply asked him if he was cold and he said no.
I thought why would someone be shaking like that and breathing how he was. I remembered the mental health first aid course and the panic attacks. He was upright and quite lucid I was sure he wasn’t having a heart attack. I talked to him some more. I noted that he was breathing too fast. He told me that he kept thinking of terrible things that might happen. I was sure he was having an anxiety/panic attack.
I reassured him I reassured him very well, I was sure what was going on, I told him about anxiety and adrenalin and how it can affect the body. We talked and talked. I asked him if he would try the breathing exercise the one armed seagull. He agreed. We did that and we did that for a long time. And we talked after 20 minutes or so of talking and trying to get his breathing normal things improved. I think the talking and distraction along with the breathing worked very well.
After half an hour of so he was much better. I told him that this was very common and that his GP could help. I said he should go and tell his GP about his.
I had to go but told someone near that he had just had a big fright and could do with a friendly ear. When I left him he was chatting to this woman. That is all I did, I think I did ok.