Did everything on your list and still can't get dpkg to load. Now it says it is being used by another progran.

david@david-MX6422:~$ ubuntu-support-status
Support status summary of 'david-MX6422':

You have 2104 packages (100.0%) that can not/no-longer be downloaded
You have 0 packages (0.0%) that are unsupported

Run with --show-unsupported, --show-supported or --show-all to see more details
david@david-MX6422:~$ cat /etc/dpkg/dpkg.cfg.d/multiarch
cat: /etc/dpkg/dpkg.cfg.d/multiarch: No such file or directory
david@david-MX6422:~$ dpkg --print-foreign-architectures
david@david-MX6422:~$ sudo grep -R proxy /etc/apt/*
[sudo] password for david:
david@david-MX6422:~$ grep proxy /etc/environment
david@david-MX6422:~$ echo $http_proxy

david@david-MX6422:~$ echo $ftp_proxy

david@david-MX6422:~$ grep proxy /etc/bash.bashrc
david@david-MX6422:~$ grep proxy ~/.bashrc
david@david-MX6422:~$ cat /etc/apt/apt.conf
cat: /etc/apt/apt.conf: No such file or directory
david@david-MX6422:~$ sudo fuser -vvv /var/lib/dpkg/lock
                     USER PID ACCESS COMMAND
/var/lib/dpkg/lock: root 6095 F.... dpkg
david@david-MX6422:~$ sudo fuser -vvv /var/cache/apt/archives/lock
david@david-MX6422:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.3 LTS"
david@david-MX6422:~$ uname -a
Linux david-MX6422 3.19.0-49-generic #55~14.04.1-Ubuntu SMP Fri Jan 22 11:23:34 UTC 2016 i686 athlon i686 GNU/Linux
david@david-MX6422:~$ sudo rm /var/lib/apt/lists/lock
rm: cannot remove ‘/var/lib/apt/lists/lock’: No such file or directory
david@david-MX6422:~$ sudo rm /var/cache/apt/archives/lock
david@david-MX6422:~$ sudo rm /var/lib/dpkg/lock
david@david-MX6422:~$ sudo cp -arf /var/lib/dpkg /var/lib/dpkg.backup

david@david-MX6422:~$
david@david-MX6422:~$ sudo mv /var/lib/dpkg/status /var/lib/dpkg/status-bad
david@david-MX6422:~$ sudo cp /var/lib/dpkg/status-old /var/lib/dpkg/status || sudo cp /var/backups/apt.extended_states.0 /var/lib/dpkg/status
david@david-MX6422:~$ sudo mv /var/lib/dpkg/available /var/lib/dpkg/available-bad
david@david-MX6422:~$ sudo cp /var/lib/dpkg/available-old /var/lib/dpkg/available
david@david-MX6422:~$ sudo rm -rf /var/lib/dpkg/updates/*
david@david-MX6422:~$ sudo rm -rf /var/lib/apt/lists
david@david-MX6422:~$ sudo rm /var/cache/apt/*.bin
david@david-MX6422:~$ sudo mkdir /var/lib/apt/lists
david@david-MX6422:~$ sudo mkdir /var/lib/apt/lists/partial
david@david-MX6422:~$ LANG=C;sudo apt-get clean
david@david-MX6422:~$ LANG=C;sudo apt-get autoclean
Reading package lists... Done
Building dependency tree
Reading state information... Done
david@david-MX6422:~$ sudo dpkg --configure -a
Setting up bcmwl-kernel-source (6.30.223.248+bdcom-0ubuntu0.1) ...
Removing old bcmwl-6.30.223.248+bdcom DKMS files...

-------- Uninstall Beginning --------
Module: bcmwl
Version: 6.30.223.248+bdcom
Kernel: 3.19.0-49-generic (i686)
-------------------------------------

Status: Before uninstall, this module version was ACTIVE on this kernel.

wl.ko:
 - Uninstallation
   - Deleting from: /lib/modules/3.19.0-49-generic/updates/dkms/
 - Original module
   - No original module was found for this module on this kernel.
   - Use the dkms install command to reinstall any previous module version.

depmod.....

DKMS: uninstall completed.

------------------------------
Deleting module version: 6.30.223.248+bdcom
completely from the DKMS tree.
------------------------------
Done.
Loading new bcmwl-6.30.223.248+bdcom DKMS files...
Building only for 3.19.0-49-generic
Building for architecture i686
Building initial module for 3.19.0-49-generic
Done.

wl:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/3.19.0-49-generic/updates/dkms/

depmod.....

DKMS: install completed.

q

LANG=C;sudo apt-get -f install

LANG=C;sudo apt-get --fix-missing install
david@david-MX6422:~$

david@david-MX6422:~$

david@david-MX6422:~$ LANG=C;sudo apt-get --fix-missing update -o APT::Cache-Limit=100000000
LANG=C;sudo apt-get update -o APT::Cache-Limit=100000000 && sudo apt-get dist-upgrade
find /etc/apt -name '*.list' -exec bash -c 'echo -e "\n$1\n"; cat -n "$1"' _ '{}' \;
sudo dpkg --audit