Help! I worked out too hard and I'm nauseous

To the point of vomiting. I've thrown up once, and I feel it coming back. I'm 22, Female, ~145lbs. I just want to tone up and get stronger, so I went with a friend who works out, and he led me through a bunch of different leg exercises. I thought I should push harder and do more, so I did. Especially since someone else was there, I felt the need to push even harder. Everything I've read says to drink and or eat something because my body needs it after working out, but I'm throwing everything up and I don't know what to do. How do I relieve this nausea and did I actually push too hard (or am I just overreacting)?