I would recommend going to see your primary care doctor
about this issue. The combination of pain in your throat together with a lump in your neck for a few days suggests to me that you are probably developing a throat infection. The lump in your neck is most likely a lymph node, as these tend to swell up when the body is fighting off an infection.
There are several different types of throat infections. The most common are viral infections like the common cold, which typically have a lot of other symptoms along with throat pain, such as running nose and cough. There are also bacterial infections of the throat. The most important of these is strep throat, and ruling out this possibility is important because it can be treated with antibiotics. Strep throat typically causes severe sore throat
without a lot of other "cold" symptoms like cough or running nose.
Your doctor will be able to examine your throat and help figure out whether or not this is a condition that needs treatment or whether it is just a common viral infection that will run its course without intervention. Please make an appointment to be seen as soon as you can!