welcome to HCM!
After reading your question it seems like both of you were ok prior to all this, so, most likely it is related to what you ate/ drank last night, which has lead to stomach upset
. looks like food poisoning
It is not serious condition but you should visit a doctor, get blood counts and start some antibiotics straight away. Your son is still having vomitings, so it will be beneficial that he takes injectables antiemetic and antibiotics first two shots and later may switch to oral medicines.
It is unlikely to respond with any home remedy, and meeting a doctor is a must.
You may go for ultra sound
abdomen of after examination your doctor says so.
so, please see the doctor and get the right treatment. I can assure you from my clinical experience that it will get better with first dose of medicine only!
Hope the reply is helpful
feel free to ask more queries.
Dr. Manisha Gopal