The type of connection does not determine what signal is being transmitted. Don't assume that and f-connector is satellite and a belling-lee connector is terrestrial.
You need to start tracing and labelling your cables and drawing a diagram so you can make sense of it. In your loft, you have a distribution system. I presume the power supply for the amplifier/distibution unit was in sitting room. Just to repeat,
PSU in sitting room.
Amplifier/distribution in loft.
When the Sky Q was disconnected, you also disconnected the power supply for aerial distribution by accident. Im guessing, I could be wrong.
One of your pictures in the loft also shows a shotgun cable, which I presume is used for satellite. Follow the shotgun cable in the loft, where does it end up? Be careful not to step on something you don't want to.