You need to take thyroxine(thyronorm)  tablet on empty stomach, first thing in the morning. You are having hypothyroidism.That means your body cannot produce enough thyroxine to meet its demand in pregnancy. Taking Thyronorm tablet will not only prevent you from bad effects of thyroxine deficiency on weight, skin, hair, heart, moods etc it will also prevent baby from its bad effects. In patients severe untreated deficiency of thyroxine I.e hypothyroidism, baby may become mentally retarded. Vomitting in pregnancy is known to increase as pregnancy advances. But usually it lasts only till 3.5 months...... You can seek help of your gynecologist to get more medicines for nausea, vomits.