It seems like you have been through some problems because of brushing your teeth and residue of saliva getting into your stomach. Vomiting can occur due to getting rid of the stomach or the reaction to much saliva. Being well-hydrated and refraining from eating a lot can help. Ginger tea or clear broths may ease your stomach. Should the initial signs persist, or if they worsen, or in case you have additional manifestations like high temperature or sharp pain, seek help from a doctor for a detailed examination. In the end, health is everything, and a doctor can help you the most in terms of your situation. Get well soon!