Hello thanks for asking from HCM for your health related queries I can understand your concern. You are suffering from diabetes and are on Metformin for this. For sleep over all most of benzodiazepines or z-drugs can be used. Ambien is Zolpidem and the drug belongs to z-drugs. The drug is commonly used for management of early insomnia. The drug is a good sedative and hypnotic but it is not very useful in anxiety and its not an anti-anxiety drug. Valium (Diazepam) and Xanax (Alprazolam) both drugs are benzodiazepine drugs and are safe to use in diabetes and these drugs help to beat anxiety. Both of these drugs are good hypnotics also. If anxiety is also main issue for you then in my opinion either valium or xanax would be better alternative for you instead of ambien. Please visit your doctor again and ask for new prescription if needed. Thanks, I hope this helps you. Take care