if your fever is normal then it might have been due to some stress
due to more work..
u can better take diclo -k tab to get relieved of ur backache
and of course u can even take antacid
.. i dont think u should start any antibiotics right now as there is no clear indication or diagnosis for that ..
if with these medicines ur not relieved or getting back ur fever again go for blood tests and rule out any typhoid
or any infection..
al the best ..