You should get detailed blood tests done. Detailed history is needed. Consult online for detailed tests .
For time being eat fresh fruits vegetables. Stay away from dairy products like cheese, butter mayonaise. Also don't take fast food.
Sleep well for 8 hrs. Walk for half an hour. Drink water well.
Also take a multivitamin with
calcium and
vitamin D3.
Bcomplex deficiency gives mouth ulcers
Also to improve digestion and hunger you need to get
liver function tests done.
Consult online for medicines to stimulate the liver.