You sound just like I did in nursing school,my hands shook so much when I was trying to insert a foley in a woman I that it was impossible for me to get it in (LOL?) but my instructor was very understanding,in a stage whisper she just said "relax,you're doing fine".
I also looked very young,I was 22 and looked 18 or so. I had experience as a CNA and started work on a busy surgical floor where once the staff there knew I could pull my own weight, they supported and helped me.That helped give me confidence because I was just sure that I didn't know anything.
I also lost 40 pounds in nursing school,it was/is rough.
You sound like a very conscientious and caring person we need you. Welcome!!