Pruning wisteria - am panicking after radical short sides and back

[PacificDogwood]

Please tell me that wisteria needs to be pruned back hard twice a year, yes? In January and July or thereabouts?

Mine is about 15 years old, languished for almost 10 years in a pot in which it barely grew and certainly never flowered.
Ever since it made it into a bed 3 years or so ago, it grows and flowers phantastically well

I have just pruned it back and OMG it is looking sad.

I am just looking for some reassurance. Or otherwise, if need be.

Hello pacificdogood,don't worry,your wisteria should recover. By pruning in late summer (prune back the long summer growth and the lateral stems-the ones shooting off the long growth) you are helping the wisteria divert it's energies from producing lots of leafy green stems into producing flower buds for next year.
Try to train in the main stems to a horizontal network,as this also aids flower production.
In winter prune back the short flowering stems to 2 or 3 buds(the rhs recommends) and prune back any long shoots that grew after summer pruning to about 15 cm.
Maybe give it a bit of a feed,some blood fish and bone,growmore or seaweed meal but not too late in the season as you don't want the soft new growth damaged by frost.
May your wisteria have a most floriferous 2013!