Anyone on seroquel (preferably long term) have luck going off?

Long story short, I was 13 when I was first diagnosed and they put me on seroquel. Over the next 12 years I was tapered up to 500-600mg. I finally got a new NP (who listens to me) and we came to the conclusion I have ADHD and not bipolar, especially since going lower on seroquel and adding the right meds has done nothing but make me more stable and the chronic depression I had since age 11 has vanished . All i'm left with is trying to get off the seroquel. I'm stuck around 100mg-150mg. Everytime i'm on 150mg it takes around 3-4 hours to kick in and make me tired, and then I go to bed and I sleep for 12 hours and it's painful to get up for work and I've been late several times. When I drop down to 100mg I seem to have some insomnia where I never get tired and I lie in bed from 11-4am just restlessly before taking some melatonin or hydroxyzine which barely tips me over the edge. But I wake up much better and completely able to function. Has anyone had any luck tapering off seroquel and if they have insomnia what have they done? Are there any other side effects people have noticed?