Welcome to HCM
First of all I want to know the name of the medication and duration you received via intramuscular route.Usually diagnosed case of typhoid
needs at least one week (sometimes two weeks) antibiotic medication(oral or injection).another thing is that when long duration of injection is need it should be given via intravenous route not intramuscular as it may cases severe pain
and intramuscular injection
is less effective.
Now about the lump formation it is quite common for intramuscular injections and usually needs no treatment as it is self limiting most of the time.