Ambien and zolpidem

I took Zolpidem (Ambien) last night for the first time. It was prescribed to me by my oncologist as I have been having trouble sleeping ever since I have started chemotherapy for breast cancer one week ago. I fell asleep quickly and slept well for 5 hours, but awoke at 2am with a headache. I took 1 gram of Tylenol at 2am but was unable to go back to sleep because the headache became increasingly worse and did not go away until I drank some coffee at 5am. It was the worse headache I have ever had. The caffeine made it go away finally.

I TAKE ZOLPIDEM (AMBIEN) - THE SIDE EFFECT IS TINGLING IN MY LEGS

I have been taking Zolpidem for about 6 years now (Half a 10mg tablet) at night it can make me feel quite groggy the next day if I take a bigger dose, but one side effect it does have is that it makes me feel starving!!! Does anyone else experience this.