Fibromyalgia Syndrome :: Cymbalta/Duloxetine For Pain Not Depression

I had a very successful pain clinic appointment yesterday, by successful I mean i saw a Dr who wasn't a complete arrogant idiot, he was very nice and tried to think out of the box a little. I asked him for lidocaine patches and although he said he did not think they would work because of the pain being deep he was willing for me to try them, he couldn't prescribe them so he's written to my GP, he also suggested capsaicin cream and finally he thinks i should try cymbalta/duloxetine. I explained that id tried various anticonvulsants and hated them due to side effects and that i was not depressed (i probably should be) but i'm not, i get angry more than sad for the chronic situation but i don't feel hopeless and apart from super hellish days i cope fairly well. 

The thing is my little boy is my world, i'm so concerned taking an antidepressant when i don't feel depressed will kick off depression, especially if they don't work and i come off. I used to suffer with depression when i was younger and i know how horrible it is and when your i was in that cycle nothing or no one mattered anymore so i'm concerned as i'd rather continue to live in daily pain knowing my son is getting the "real" me than be on any meds that might change how i feel or how i am towards him. 

Does anyone have experience with these specific meds? Especially taking them for just pain and not depression?