Why is this happining?

Well I spent the day at six flags today it was fun and only one of my firiends did not feel good, we ignored him and he sat out. We rode alot of stuff and it was hot out kind of. I hade 8 bites of a funnel cake and lots of water. When I left I hade chicken nuggets from Berger king. I went home feeling tired with a headach. Now it's 11:30 and my stumach hurts bad, and dame with the people that I went with. We all kinda feel like vomiting to. I have no idea what is going on, I'm even somewhat scared. Please help! (I have been to six flags more than 50 times and this is the first time we feel like this!)