Okay...you were working on a very stressful part of a job that is new to you...stress and adreniline is high, lots of confusion and things to do with no time. Gee go figure you would cry afterwards...you are HUMAN! It is a release from all you just went through...and since you are new that is 10 or more times greater for emotions by just the stress alone!
One thing to try...after a code or stressful situation...take some time and go to the bathroom and cry it out! Crying is a natural release, and it takes a ton of energy to bottle that up! I don't cry at codes (typically I am hyped for hours after one), but there are many other things I do cry about that hurt me at work. I take the time to release and refresh...or I will be no good to anyone..and I do this for others as well (if I see another staff about to cry or I know they are holding back on something I will help cover so they can take some time for themselves...it is part of teamwork!).
Another thing...and the reason I don't cry at codes...is I realised by the wise words of paramedics and nurses..."if a patient isn't breathing and doesn't have a pulse..they are dead...so anything you do afterwards is a bonus...considering there is only one being we know of that can bring back the dead...this is pretty impressive if we can! So do your best...rest assured you did...and take time to appreicate the work of others with you that tried!". I think that really gave me a great mindset!
Also, looking into how you view death yourself is essential. I have told this story before, but I had an AWESOME teacher that had us fingerpaint a piece of paper at the begining of nursing school that represented death. All the colors were dark and drab and depressing. Then a few weeks before graduation, she supplied the paints again with a heart shape paper and had us paint what we felt about being nurses and helping people! All the colors were light and cheery! Then she took the hearts, put them on the background page we made at the first of our schooling and laminated/framed them and gave it to us on the day before grad. This represented our feelings of death, but our thoughts about ourselves and our abilities that overcome it! And she was right...the background was there, but the heart took center stage...a simple thing, and put things into a really neat perspective!
Now, I know you may not be able to do that right now...but knowing your place in the cycle of life/death really helps! You will do your best, but it isn't something you can overcome when it is time. Best to focus on your HEART, and not the swirls of greys behind it
Hope that helps