But, if you still have a very prolonged FEVER and are feeling sick, then you need to check for ANTIBIOTIC RESISTANCE, and maybe have a CT scan of the abdomen to r/o an ABSCESS that might require surgical drainage. This would be a scenario where the blood cultures reveal bacteria SENSITIVE to the antibiotic you are on, but you still have fever. An abdominal ABSCESS may not respond to just antibiotics, even though the bacteria shows sensitivity to your antibiotic. In this type of case, you must look for ABSCESS and drain it if it is found.
As for your SYMPTOMS, you may need to take Tylenol or an NSAID for the fever and headaches. As even proper antibiotic therapy will TAKE TIIME to get you well. But be SURE your antibiotic is active against SALMONELA TYPHI -- assuming THAT is what you have (again, this is usually proven with POSITIVE BLOOD CULTURES WITH ANTIBIOTIC SENSITIVITIES).