Yours doesn´t look like this?
Maybe it is not a fosteriana at all.
Dyckias fosterianas are all superb plants.
But they all have a particularity an eccentricity that is fatal to its perpetuation when out of its wilderness place: This plant doesn´t clones! So the only way to multiply this baby is relying on its seeds and seeds are not trustable things.
That is why yours barely resembles this one here. If it does at all.
Take a look around the Net and you will promptly see what I mean.