Did you check in backpacks, the homestead chests, etc? There is a pouch container that has the same icon as a pouch of bonedust or moondust.
Check Evelyn's house, as well, in case you ended up reloading an earlier save for some reason, and didn't re-loot it from the chest.
Did you check older saves, if available, until you found the most recent one with the spell, and oldest without? Knowing when it went missing could help determine what happened to it (dropped when organizing inventory, etc).
If there are a limited number of places where you may have been sorting your inventory, checking there with the Alt key pressed could help find it (X in the Linux version, or with Show World Tooltips toggled on using a controller).
If you can not find the scroll, reply to the support email with your latest save.
