I Am Taking Cymbalta For Pain And Have Been Experiencing

I am taking cymbalta for pain and have been experiencing hallucinations at night, which I noticed shortly after starting this medication. I was also given Flexeril at take for muscle spasms. Which med is more likely to be causing this symptom? I am very sensitive to many medications, for example Zenaflex caused very rapid eart rate and inability to sleep, as well as hallucinations. I am 60 years old.