Bug/Issue Missing Pickaxe

My pickaxe disappeared. I didn't get knocked out in the mines, just woke up one morning and it was missing from my inventory. I read someone said if this happens it would be mailed in a few days but I've waited several days and nothing has happened. Is there anything I can do to get it back? I've sunk forty hours into this farm it'd be a bummer to have to start over.

 

Probably the simplest fix would be to make a backup of your save (always make backups) and then use this inventory editor to add it back in:

http://community.playstarbound.com/resources/stardew-valley-save-editor.3461/