Confidence?

Hi all.....I need some help. I recently came off of orientation and besides the regualr panic attacks I have before going to work in the morning about what type of patient I am going to get :), once I am at work and involved in care I begin to feel ok. However, I often find myself REALLY wanting to make a decision (a very small one at that) (for example take a rectal temp to confirm the axillary temp is accurate on a baby), to take control and there is a tiny voice that says "go ahead and do what you think you should do" however the other part of me says "don't push it. you are just off orientation and have no idea what you are talking about and you may hurt someone" (because I am afraid of doing a rectal temp on a 2 week old baby for fear of doing damage). I feel like this is holding me back a lot. And when I come home from work I look back at my day like I should have done a lot of things differently. Sure, my patients are ok at the end of my shift, but was the care I gave good enough to keep them safe through the next shift? Will another nurse have a bad night because I didn't follow up enough during the day? My question is how do I gain just a small amount of confidence to move forward with my decision making in order to improve the care I provide my patients? I am learning from my mistakes (they have been very small ones thank goodness) but I am afraid if I keep holding back it could lead to a bigger mistake. Any advice would be appreciated:) Thanks:)