I have insomnia and had been using ambien (zolpidem) for a while. i have to take 4x 10mg tabs just to get to sleep. i have spoken with my pcp and am now trying diazepam 4x (5mg) any helpful advise.

Withdraw: You have a serious problem. Physical and emotional habituation are likely. Diazepam is worse than ambien (zolpidem). Look for alternatives with a sleep medicine physician's help. If there is an underlying physical disorder of sleep, a polysomnogram may diagnose something that can be specifically treated. Behavioral measures ("sleep hygiene") may also help, such as regularizing when you go to sleep daily.

Both Unwise: Both methods treacherous as you become unable to sleep without medication as both Ambien (zolpidem) and valium (diazepam)-- causes rebound insomnia. This means in addition to what ever was your original struggle with sleep, you now have a new one--use of either medicine more than 2 weeks will cause withdrawal if stopped. There are other medicines that grant much safer sleep: ask for them!

Insomnia: Has the cause of your insomnia been explored?. Treating the cause is way to go.