How do I know if it’s an orgasm?

Just last week, I finally figured out a sort of makeshift vibrator—the best I can do for now—and I tried it out for the first time today. I did achieve a sensation stronger than what I’ve experienced before (that same pseudo-orgasm pleasure response that I have every time). My legs shook involuntarily for maybe two seconds, I think I sighed (I never vocalize while masturbating, so this is a clear difference) and I felt the rush. The only thing is, though, that I didn’t lose as much control as people describe and it wasn’t as earth-shattering as described, which makes me think that it isn’t an orgasm. I enjoyed it very much, but whatever that was would have been a poor example of an orgasm. 

Right after, I removed the vibrator and stopped. I know that women can achieve multiple orgasms, but making it past this moment of pleasure was a bit difficult, I guess...? Do I have to continue on to achieve what would probably be a real orgasm? 

Another question: has anyone else felt sort of scared trying to achieve orgasm? I felt nervous of my body taking over (I am EXTREMELY calculated and aware at all times and am uncomfortable giving myself away). This nervousness might’ve been similar to a someone-might-tickle-me nervousness. 

I’d appreciate your feedback so much if you’re willing to give some input! I’m eighteen and gay and I’d really like to figure this out.