How to stop olanzapine without permanently suffering from insomnia?

I took a dose of 10mg of olanzapine for 4 years, I read about the various symptoms it can cause, several people have tried to stop and were unable to, I was very frustrated, I tried to reduce the dose by half every two weeks but it didn't work, it gave me severe insomnia and I had to start taking it again after 4 days, I would like to know if anyone has actually managed to stop after taking it for a long time, and if they felt well without needing to take another medication.