Hi thanks for your question
You have two issues. Lump inside your throat, associated with fever and chills and you think it is lymphoma.
Second issue 
indigestion and burning pain abdomen.
I think your Doctor may be right, it could be 
pharyngitis (infection of throat) caused by streptococci. It is not necessary, that you will go out and only then you will get 
streptococcal infection, you can get it even at your home.
 Try a course of antibiotics and antihistaminic and decongestant ,hope fully you will get rid of these symptoms, if you symptoms remain persistent after a course of treatment ,only then, you can get  yourself tested  for lymphoma.
Your indigestion problems could be due to 
Gastritis, Take  a course of 
pantoprazole and discuss it with your treating physician and you may need upper G I endoscopy.
Hope this answers your question