Happened to me to a long time a go!
never do
apt-get dist-upgrade
on a phone, only
apt-get upgrade

apt-get dist-upgrade upgraded on package which is not compatible with other packages, and you got a warning from apt-get which packages will be upgraded and which deleted.
You answered: Yes ;-)

Now you need to reflash.
Content of the Internal eMMC will not be deleted, but all other things.....