When did the symptoms come back?
Sounds to me that you have a viral upper respiratory tract infection - this is far and away the most common cause of sore throat.
Most likely you have simply been unlucky and caught more than your fair share of infections this particular winter.
Other causes for persistent sore throat include reflux disease and chronic nasal congestion. A persistent one sided sore throat - ie lasting 4 weeks + needs a thorough exam by an ENT specialist.
Please get back to me if you need to.
PS if you nose is congested taking a decongestant will often help an associated sore throat.
I do have GERD and I've been taking something for the congestion. I do have an area behind my last tooth on that side (where my wisdom tooth used to be) that is sore and swollen.
What could the persistent sore throat be?
Are your symptoms persistent - ie present day after day for several weeks or intermittent?
What are you taking for your GERD?
Persistent pain can be caused by GERD, nasal blockage, dental caries and much less often tumors.
As mentioned already the most probable cause is simply another viral infection.