Hello, i have a constant stomach ache and always feel like i'm going to vomit. any ideas of what it could be?

Need to see a doctor: Many things can cause stomach pain and nausea. Some of those need immediate medical care like acute pancreatitis, acute cholecystitis, gall bladder infection or a heart attack. It can just be as simple as uncontrolled reflux disease, gastritis or an entero-gastritis. Your local doctor need to go over your specific symptoms, history and its severity to give you a proper diagnosis and treatment.