Januvia and severe pain

I have severe pain in my throat near my jaw and ear. The attack lasted 20 minutes to 1 hour; it was like a seizure. After I take the pain killer, the seizure stops and I am going to the doctor again this morning.

I've been taking Januvia for 8 weeks, and have experienced muscle cramps with shock-like pain running down my leg into my heel; upper and lower GI spasms; night sweats with sleep interruption; and I gained 5 pounds in the first 4 weeks which I can't attribute to anything else. I've also taking metformin and glyset for several years, and although I've experienced the night sweats, they've greatly increased in intensity.