As you said you ate peanut butter and might have been ingested with salmonella(typhi) the symptoms (fever, vomiting, stomach pain) could be caused by that infection(enteric fever
). But you should also rule out other diseases as mentioned because kidney infection
also can cause you fever, burning micturition, polyuria. Get tests( widal test
for salmonella antibodies
) done for enteric fever.
Have good ORS, garlic foods from your home.
Have a good Health, Dr. Praveen.