From a dude who's been there...

There's basically 3 reasons dudes get sick in airplanes:

1) nervousness. Anxiety sometimes makes you wanna puke. If you got wigged out by an unexpected spin entry, that might have contributed to it.

2) you are worried about puking. I'm not kidding. I've seen more dudes puke in jets because they thought they would than any other reason. If you get it into your mind that you might feel sick, you will. You will subconsciously be looking for any little hint that you feel sick, then your mind will run with it until you are.

3) you are just sensitive to it. This can usually be overcome by just continuing to go up in the air and expose yourself to the problem until you become desensitized to it.

You'll get all kinds of advice. Most of it is cr-p, to be honest. I was told to eat nothing but saltine crackers all the way up to eat a giant bowl of chili right before you fly. Point is, if you think it will work for you, then it might. A lot of it can be mental.

In case it helps, I used to get sick in cars, in Cessnas, and I got sick about 7 times in USAF pilot training. I was just sensitive to motion my whole life. I got over it and I am now an F-15 instructor pilot where I can now stand the most gut wrenching stuff aviation can hand out without any issues. I wanted to be a fighter pilot and I was going to keep trying until I got there. Eventually I just got over the motion sickness, but the Air Force has a program to help. It essentially involves spinning you in a chair (called a barany chair) and then making you move your skull around to induce tumbling sensations. It's hell on earth, but it works to desensitize you quickly. I know you don't have that exact option, but I used to go to the park and spin on the merry go round thing for a while (close your eyes and spin until you don't really feel like you are spinning anymore, then start moving your head around...it sucks). That's pretty extreme advice and I don't think you are there yet.

Here's my advice:
1) DON'T WORRY ABOUT IT. If you get sick, you get sick. I mean that quite seriously. You'll eventually get over it, but you'll get over it a lot faster if you don't keep thinking about it all the time. Some dudes get sick. It's a fact. It's not fun, but it's also not a big deal unless you make it one.

2) Keep flying. The more you get in the air, the better. Staying away from flying for a while will make it more difficult to get over it.

Good luck