I had a relative who was taking these medications, and I found these boxes. I tried risperidone and only one was enough to put me to sleep
That is normal, Risperdone is known for making people incredibly drowsy.
I had to take my 4mg at and go to bed at 9, and would sleep for about 11 hours roughly, sometimes longer.
Would not wake up in the night either.
Quite impressive for someone with PTSD who only used to sleep for around 3-4 hours a night.
What you experienced was a normal reaction, and would definitely not kill you.