I Am A 64 Year Old Woman With Post Polio

i am a 64 year old woman with post polio i wanted to change from the Valium as I thought I had been on it too long and it wasn't as effective so my dr put me on Seroquel slow release, I have had a lot of the side effects in the last 7 days I only took 2 full 50mg I just knew not good,as instructed by dr cut the pill in half then half again I rang my dr he said to keep taking them, till he got back from holidays???? i am not and tonight will be my first night off completely what can i expect?