I have asked this about a million times but I am still wondering?

I am 19 years old so I don't think this is a silly crush. I just need more answers. I was on a cruise, and I had a waiter every night, and I don't know why but ever since I got off he is all I thought about, and I constantly have this sick feeling in my stomach at the thought that I may never see him again. I don't know at all how he may feel because he was always working when I saw him, and it was just small talk. I looked up some people who worked on a carnival cruise on facebook cause I couldn't find him specifically and I messaged them to see if they knew him. I am still waiting for responses. Do y'all think I should have done that or am I being really crazy and weird? I have never felt like this before.