Can't keep anything down!

Once I eat something less than 3 minutes later I'm running to the toilet because it's coming up. Why? It's killing me. I need to eat, I need something in my stomach. The doctor gave me meds they didn't really help but I've lost them. I forget everything since I've been pregnant & I misplaced them. Do anyone have any other remedies? Or knows why this happens so I can prevent it?