Losing Weight

I weighed about 128 before I got pregnant, now I’m 121. I’m 9 weeks now, and I’m getting scared about the weight I am dropping. My ob/gyn said it was okay to lose weight due to nausea, but she said that when I weighed 124. There are a lot of days I can’t keep anything down, and my appetite is nonexistent. Does anyone have any tips to prevent me from losing anymore weight?