Welcome newnurse39212; I mostly post on the bipolar forum, but I just wanted to welcome you. I was right where you were in 2007 prior to my diagnosis trying to fake myself through work (which also includes shift work, I'm a Gaming and Liquor Inspector). I had wished someone had told me to go see a Psychiatrist for help. I ended up seeing my GP and the anti-d's through me into a mixed state and I ended up being hospitalized for 6 weeks.
If you haven't spoken to a mental health professional yet I would suggest seeing your GP and asking for a referral to a Psychiatrist. Therapy may also help. If you feel like you are unsafe please go to the Hospital.
It's hard to reach out for help, and I would think it's doubly hard when you are in a profession that puts you in a position of always helping others. Please don't do what I did and reach out for help before it gets worse. I would also suggest taking a leave from work. I hope you start feeling better soon and I'm glad you decided to join.