I use mirtazapine from time to time to sleep and I find that if I don't want to wake up with a groggy 'hang over' effect then taking a full 30mg will keep me perkier in the morning than a quarter of that pill.

It's possible for higher doses to make someone more sedated, depending on how they react or metabolize it I assume. At the time I was taking mirtazapine regularly I was also struggling to get over 3 hours of sleep a night.

I hope things are working out better for you and perhaps another sleepy pill may help. If mirtazapine is going to work for sleep then I think it would work the first night you hit a good dose for it -- it's a bulldozer of an antihistamine.