Hi there!
Those things can definitely impair your performance but most people, including myself, have become more desensitized to it. The fact that you have learned to deal with your children is a good sign that you will get past it.
For me, it had a lot of it had to with willpower, rationalization, genuine concern for the patient and constant exposure. So let me tell you about my experience.
I willed myself to face my fear of sharp objects. The very first time we were handed syringes, I was scared silly. This was in a classroom, mind you. All we had to do was open them up and draw up water from a practice vial and ampule. That's it! No sticking people yet. When I was taking the cap off to expose the needle, I became really lightheaded. During the exercise, I reasoned with myself and so while I was drawing up the water, my mind was going "You are in control of the needle! If you just steady yourself, you will not hurt yourself. You cannot be like this in front of patients. *They* will get hurt."
As for odors, feces, urine and such, I encountered a lot of that in long term care facilities. For the first few times, the primary feeling in me was "I HAVE to take care of this patient" and suprisingly enough, I had no more room in my head to go ew, yuck, gross, I'm not doing that. Over time, I really have been desensitized and believe it or not, it has only been nine weeks into my nursing program.
So the point of this little novella is that most people do get past the fear and disgust. This does not mean that they are not there but rather that these nurses have gotten to a point where their will to do a good job is a lot bigger than the urge to turn away. The only way, really, is to go ahead and find out for yourself if you are up for it!
Good luck!