Grevillea Olympic Flame

I have a Grevillea Alpina Olympic Flame. which we bought as a reminder of a holiday in Perth, WA. I put it in a pot at the front of the house in a sheltered position, but in half and half shade. I thought it would be ok there. It immediately started looking poorly so I moved it in to full sun. Still no joy and I have had to watch as it slowly but surely gets worse. What should I do? I know it has to have acid soil, no feeding just water. I really would like to save this plant if anyone can help.

 

Only grown G. "canberra gem", but this looks very similar.

I found it the kind of plant you just leave to get on with it, then hack back when it gets out of control.
But I was growing in the ground, not sure it would like a container, its quite a big shrub.
As to not feeding?
Not sure that is good advice.
And it would need lots of water in a container.

Have you got a picture?