My Confusion and I

I have now been a volunteer in ambulances in Israel for about 6 months actively. During this time I've seen many drunk people, old people with high blood pressure, people with stomach ache and people who I really have no idea why they called the ambulance at all but I've also seen really ill people. Some people with problems breathing and would probably stop breathing if we didn't give them oxygen, some people without a pulse, and therefore the need of CPR, and car accidents. Luckily the CPR I've done was successful and I can live my life knowing I've saved someone else's life but I've also seen people die. The first time you see someone die you don't really know how to react. My reaction was to first calm the family down because that was all I can do. However, the things going on in my mind was "oh my god, what just happend?" Did I do something wrong? What did I miss?. I couldn't get it of my mind even though we did everything we could. I