Congested Wi-Fi

Hi y'all.I've recently (3 months ago now) moved house, and the new location has an amazing knotwork of WiFi networks. It's gotten to the point where any of my devices trying to connect via Wi-Fi have a really poor experience. For what it's worth, the network has:

1x laptop

3x Android devices - Nexus 4, Nexus 7 (2012) & moto g

1x PC - used to be connected via Wi-Fi but have changed to ethernet

1x Xbox 360

1x Xbox One

The wireless congestion looks like this:The congestion gets so bad that my Android devices will actually refuse to connect to the network, citing "Temporarily avoiding poor connection".My router is a Slingshot-supplied NetComm NB604n.I've had a play through the router settings, but I don't fully understand about 3/4 of the Advanced wireless settings.My initial attempts were to:

Set the Channel to auto

Enable OBSS Co-Existance

But I don't know if these have really helped at all.Can anybody suggest ways to improve our wireless network?