EXTREMELY DIZZY! HELP! WHAT HAPPENED?

Hi. My name is Shyan and I am 18. Today I just started my period as normal (every month it has been normal) My cramps were really hurting so I took 2 midol like I've done before. Then I started feeling tired so I went to a coffee shop right by my work so I could wake myself up before work. I work at a hospital as a Tray Passer. So I get there and I start to feel sick in my stomach. Very achy. And then I started feeling dizzy. I wasn't too concerned at first just thinking it was just me being tired so I went down to the cafeteria in a faster pace so I could get my heart pumping so I could wake up. I get a cart full of trays to take up and as I walked to the elevator I started feeling worse. Extremely worse. The more I moved, the more dizzy I got. Every tray I gave to the patients made me feel uncomfortable because I was scared I might faint and hurt a patient by dropping hot soup on them or something. So I head back down to the Cafeteria and tell my manager my concern. She says to sit for 15 minutes and see if it helps. So I got a glass of water and sat down for 15 minutes and got pretty emotional because I still felt so bad. It did help my dizziness but not my stomach. So I got back up and tried taking another cart. Started feeling horribly dizzy again. My anxiety grew because I was so scared I was going to hurt someone. So after I was done with that cart I went back down and told my manager I was going home and having someone drive me home so I wouldn't hurt anyone and just be safe. She said okay so I went home and my dad drove me. I am really concerned with what happened to me and how I can avoid it from happening again. I really wanted to work today so I could make more money. But I did not feel right and I felt like I was endangering people. What happened to me?