Is this an anxiety or panic attack? If so what can i do!?

First let me explain how i think this all started. I am a surgical technologist and I love what I do. One day when I was in clinical I started to feel really weak and hot and started getting tunnel vision or "blacking out." I had to sit down quickly because I thought I was going to pass out. This was the first time I had ever done this and i'm thinking it was because I didn't eat anything that morning for breakfast and I was in surgery and just got weak (it wasnt the operation at all). It really scared me though. Now I am scared to death I will do it again. So....now all of the sudden when im in surgery I will think about that moment when i did that and ill start doing it again for no apparent reason!! My heart will start beating really fast, I'll start getting tunnel vision again, I get really hot and sweaty. I'm pretty sure this is because my blood pressure is dropping. The tunnel vision is what is most scary cause you start blacking out and could fall over from it. It feels like a panic attack! (even though there is nothing at all to panic about) But somedays I'm ok and won't do this. I know it's a mental thing. I make myself do this by thinking about it but I can't help it! I have no idea what I should do about this. Is there any medication? I try so hard not to think about it but when I do its like it triggers me to do it again for no reason at all! I'm pretty sure it's an anxiety attack or panic attack I am having. I dunno what to do about this because I don't do it all the time but when I do it's horrible. What can I do?