I have been taking less than 25 mg of Seroquel for a long time as a sleep aid. I used to separate it in half and a little piece would be sufficient to help me sleep.

I am now in a depression relapse with anxiety and I take 50 mg. I have no trouble falling asleep but I wake up in the middle of the night, unable to fall back asleep. My sleep quality is bad and I also wake up early at the same time each morning. I feel like I haven't had a decent night of sleep since 2 months. My psychiatrist suggested to replace Seroquel by Ziprexa (Olanzapine).  

I'm afraid to change medication and worsen my insomnia. For those who take Zyprexa for sleep, does it improve your sleep quality ?