Did you just start using a juice with higher PG in the ratio (lets more nicotine hit through), or higher nicotine, or cinnamon or pepper in the juice (another throat irritant) or start using a stronger battery or LR cartos (hotter), or dual coils (double vapor)? Because I can't imagine what after 2 months would suddenly make your throat sore if you haven't changed anything unless you started
vaping more or were not staying hydrated.
Nicotine is a fairly strong skin irritant. Having some VG in your juice can help buffer that. But you still have to stay hydrated. And if you are overdoing vaping, consider a lower nic level for times when you are vaping a lot. I use 80PG/20VG in cartos but when I was on higher nic I use 70PG/30VG and my cartos didn't last quite as long.
Note though - there seems to be a lot of flu and strep throat around based on how many people on social networks seem to be sick. So that is also a possibility, especially if you have school age kids or sick relatives/coworkers.