NEDERLAND WOOOOO!
Anyway, try sizing down everything, if you don't want to start all over. Remove all "meh" characters and rooms first of course.
And also, backup your savegame. Religiously. Won't do you any good now, but it will in the future.
Here's how:
Get into your file system (depending on your manufacturer you might need to get one from Google Play, like ES File Browser) and go to
/storage/sdcard/android/data/com.gamesas.falloutshelter/files/VaultX.sav
where the "X" in VaultX.sav is the number of the vault in question from top to bottom in your savegame list in-game (so 1, 2 or 3)
Copy and paste that daily/every other day to a safe location or email it for all I care, but that way you'll lose little progress and/or boxes.