I am taking lyrica75mg & Effexor (venlafaxine) 75mg to control fibromyalgia, but the horrible pain in neck&shoulder especially the left shoulder led me wish to die!?

Look for Causes. All of the previous answers are great! You should also be evaluated for underlying causes of pain such as myofasciitis (trigger points), ligamentous injuries and other arthritic conditions. Trigger points are extremely common in this area and respond well to simple interventions such as "spray and streach", deep-tissue massage and trigger point injections if the above treatments doesn't work.
Fibromyalgea. Lyrica and Effexor are indicated for fibromyalgia but are not magic pills. It may take several months and higher doses before you notice benefit. Cymbalta or savella (milnacipran) may be more effective than effexor. Psychiatric problems may exacerbate the pain perception. I suggest that you see a psychiatrist asap if you are considering suicide. Increased social and physical activities may help as well.
Don't "feed" the FM. Even tho' it will take longer, try eating a diet with foods as close to their natural state as possible - that means nothing with labels, no refined sugar, wheat, etc. Try strictly eliminating all dairy, gluten, soy for at least a month, or a real "elimination diet" that can be found online. Try some d-ribose (5 grams 3x/day), vit d 2000 ius/ day) and get to a hands-on osteopath and a good pt.