Clicking from that area sounds like the lift pump - diesel sold in the UK during the winter won't wax up, it takes more than that for it to wax up, it will thicken a little.
The extra pressue has probably caused a failing lift pump to fail, the ticking is probably the little arm flapping about (it breaks).
Undo the bleed nut on top of the fuel filter housing and pump the lift pump a few times (if there is no resistance and no diesel emerging from the bleed nut then blimp the engine on the starter to get the pump off cam and try again).
Or, the easy way - undo the bleed nut and get someone to turn the engine over, fuel should stream from the nut.
Changing this pump is simple.
If you get a new one make sure it comes with new olives and nuts - Craddocks sell them seperatly - assuming your pump is the original part and someone hasn't just used pipe and pipe clips - you too could do it this way but its much neater to do it properly.
If you get to the stage where you CANT get any diesel from it, then I would say its the pump. Get a GOOD replacement pump (not britpart) £25ish.