Can't Update Securely and Is Therefore Disabled? [Duplicate]

I have been all over this thread and nothing I've read or tried fixes this for me. I had wine installed but I removed it because I didn't want to mess with it. It appears that has compromised things for me. When I do sudo apt update I receive:

Err:1  disco InRelease
  Could not resolve 'your.repo.domain'
Ign:2  stable InRelease               
Get:3  disco InRelease [6,255 B]       
Ign:4  artful-updates InRelease             
Err:5  artful-updates Release               
  404  Not Found [IP: 91.189.91.26 80]
Hit:6  stable Release
Hit:7  disco InRelease
Hit:8  disco-updates InRelease
Get:10  disco/main i386 Packages [42.1 kB]
Hit:11  disco-backports InRelease
Hit:12  disco-security InRelease      
Get:13  disco/main amd64 Packages [39.5 kB]
Reading package lists... Done       
E: The repository ' artful-updates Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

I used to be well versed in Linux but that was like 10 years ago and now I have no idea what I'm doing. Can someone please explain to me how to fix this like I was 5? I changed my server to main server.

I removed wine from the Other Software and it said to reload software so I did and it failed saying: E:The repository ' artful-updates Release' does not have a Release file. When searching sources, I see this. I'm running a backup now, as suggested in another thread, can someone help me on where to go from here? Thank you so much!!

UPDATE : content of /etc/apt/sources.list

# deb cdrom:[Ubuntu 19.04 _Disco Dingo_ - Release amd64 (20190416)]/ disco main restricted

# See  for how to upgrade to
# newer versions of the distribution.
deb  disco main restricted
# deb-src  disco main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb  disco-updates main restricted
# deb-src  disco-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb  disco universe
# deb-src  disco universe
deb  disco-updates universe
# deb-src  disco-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb  disco multiverse
# deb-src  disco multiverse
deb  disco-updates multiverse
# deb-src  disco-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb  disco-backports main restricted universe multiverse
# deb-src  disco-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb  disco partner
# deb-src  disco partner

deb  disco-security main restricted
# deb-src  disco-security main restricted
deb  disco-security universe
# deb-src  disco-security universe
deb  disco-security multiverse
# deb-src  disco-security multiverse

# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.
# deb  disco main
# deb-src  disco main
deb  artful-updates main
# deb-src  artful-updates main
# deb-src  disco main
# deb-src  disco main
# deb-src  artful-updates main
# deb-src  artful-updates main
# deb-src  artful-updates main

UPDATE #2: After running command provided by Jim

leslie@leslie-Lenovo-YOGA-720-13IKB:~$ sudo sed -i '60s/.*/# &/' /etc/apt/sources.list
[sudo] password for leslie: 
leslie@leslie-Lenovo-YOGA-720-13IKB:~$ sudo apt update
Err:1  disco InRelease
  Could not resolve 'your.repo.domain'
Ign:2  stable InRelease                   
Hit:3  stable Release                     
Hit:5  disco InRelease
Get:6  disco-updates InRelease [97.5 kB]
Get:7  disco-backports InRelease [88.8 kB]
Get:8  disco-security InRelease [97.5 kB]
Get:9  disco-updates/main amd64 DEP-11 Metadata [72.1 kB]
Get:10  disco-updates/universe amd64 DEP-11 Metadata [8,740 B]
Get:11  disco-updates/universe DEP-11 64x64 Icons [8,269 B]
Get:12  disco-backports/universe amd64 DEP-11 Metadata [7,164 B]
Get:13  disco-security/main amd64 DEP-11 Metadata [17.8 kB]
Get:14  disco-security/universe amd64 DEP-11 Metadata [1,480 B]
Fetched 399 kB in 2s (232 kB/s)                
Reading package lists... Done
Building dependency tree       
Reading state information... Done
All packages are up to date.
W: Failed to fetch   Could not resolve 'your.repo.domain'
W: Some index files failed to download. They have been ignored, or old ones used instead.