I had the same reaction with cymbalta. Just wanted to hurt everyone around me including myself. Within a day or two of stopping it, it all went away.

I've taken both. Gabapentin makes me kinda zombie like, mentally. I feel sleepy and unfocused. Cymbalta made me so depressed for the entire year of 2011 that I didn't think I would make it to 2012. I was very suicidal. As soon as I stopped taking it, (I took myself off of it) I felt more normal again. But that stuff was awful. I think it can cause headaches in some people. Other people it just makes you really depressed.

Gabapentin isn't helping me at all. I ask my doc to change my prescription every 6-9months because I am worried about addcition and my liver, but Gabapentin isn't helping me with the stabbing pains that I get, nor the lingering burning pains.

I've had a headache everyday since I started Gabapentin. I tried to get off of it as
I really don't think it does that much to help with the burning pain anyway, but the doctors are reluctant. I don't get it?

I take both.. Cymbalta made me nauseated to start but no real side effects now, but if you feel it is, talk to your doc about stopping it for a couple of weeks then restarting it. If the headache comes back, then it probably is the combo bothering you