Hello...
Don`t panic. Calm down, be courageous and get  treated. 
Without investigation it is very difficult to diagnosed  this condition. (May be its mild to sever)
Your first doctor, What he say, that is his clinical diagnosis,
Your second doctor recommended you for investigation, you have to go for that, for proper diagnosis, its important. 
My opinion:
Go for investigation, After investigation your doctor prescribes medicine if needed, complete the course.
I would Advice;
Drink Plenty of water, It will keep you hydrate 
Don't use blindly medicine.
Avoid outsides food,
Take 
bed rest.
I hope I have answered your query to your satisfaction. 
Wishing your a speedy recovery.
 
Thanks;
Regards; Dr Sagar Mhatre