Hi! I just want to reply to your question the moment I saw it. I'm currently a third year nursing student and like you, I used to be afraid of intrusive procedures like injecting someone with needles or being the one getting it. One of my goals in taking up Nursing is to overcome those fears. And right now, I think I have finally done it.
Your experience must have contributed to your fears. Don't worry about it because its always like that at first, but when you get the hang of it, you will soon be okey.Just think that you'll get revenge by being the one injecting people this time. (just kidding though)
Anyways, the school will orient you about those instruments gradually as you go on with your lessons, and they will teach you on how to use them, then you will just soon think of those instruments as technical stuff, and you will soon be in control 'cause you'll have the knowlegde, that will make you confident. But of course, your clinical instructors will not leave you alone without guidance until you get the procedures right or until you graduate.
Good Luck! I hope you'll enjoy your studies.