I put my foot through a ceiling,not all the way through I just cracked the plaster below.I tried to glue the crack in the bedroom ceiling but it didn't work and the crack is now spreading . What can I do to repair this ,the ceiling has a pattern in artex on it .

OK well if the sheetrock is really bad then you would need to replace the damaged section.

If the board is not very weak but the problem is only a crack or cracks then repair with scrim or plasterers tape. Place lengths over the crack then cover with plaster, ask your diy store for what plasters they offer, sometimes products differ. You want to cover the area to be repaired as flat as possible so that you don't creat a noticeable bump.
Wait for cealing to dry then texture the affected area to match the cealing or re texture the whole cealing... hope I helped.