I can imagine. I’ve been in this situation myself a number of times...
The biggest battle is probably already behind you, going from whatever per day, to 400mg a day.
My advice:
From this point, taper 10% daily.
So 400 - 360 - 324 - 292 - 262 - 236 - 213 (week 1)
191 - 172 - 155 - 139 - 126 - 113 - 102 (week 2)
At 100mg you have hardly any effect and you can stop.
During these 2 weeks, you will be depressed. Not severly, but you won’t be feeling ok. Your sleep will be poor. Don’t start overanalyzing your feelings, keep yourself occupied as much as possible.
After you’ve quit totally, your sleep will remain poor. A few days after you quit, you will have a better night of sleep. All will be over from this point. Your sleep will keep improving and you won’t be depressed any more.
Much luck,
Vazkor