Hello, I’m 8–9 weeks pregnant. The toxicosis isn’t severe, but my stom…

Hello, I’m 8–9 weeks pregnant. The toxicosis isn’t severe, but my stomach hurts all the time, and I feel nauseous/lightheaded in my chest. What can I do? I had the injection the doctor prescribed but it’s not helping. Sometimes I feel fine, but it starts in the evening: vomiting, pain, my stomach burns and hurts, and some yellowish stuff comes up every day. That’s it.