6 weeks 6days sever nausea but no vomiting

Amanda • Name is Amanda. Happily married to the love of my life. Mother to 3 beautiful angels, my first born Hannah passed at the age of 5 due to a chd. My other 2 was missed miscarriages. TTC our Rainbow!
What is going onnnnn, I just gag alllll dayyyy and feellll like I have food poisoning. But it just wont come out. With my daughter I vomited so much I lost weight in my first trimester. My hcg is extremely high it was 21,000 at only 5 1/2 weeks, and the doctor even believes I may be carrying twins? But why am I not vomiting? My early ultrasound went perfect so ik its viable.