Irritating Plant of the Month January 2018 - the honeymoon ends

It did not take long did it for me to find this plant irritating: the Tibouchina urvilleana I bought only four weeks ago.  I may, of course, just be unapologetically fickle (I am); but in this case I cannot decide if this plant is irritating or just plain rude.

I felt sorry for it sitting on the 'rescue me' table at a local garden centre.  It was a bargain price and I thought it was worth trying to save it.  I quickly checked what growing conditions it needed and made the purchase.  It looked a little poorly when I bought it, but not terminal.
Not too bad at all in fact.

So look at it now.
Yep, leafless.  Each leaf has taken it in turns to curl up and drop off.  I suspected the rabbits of nibbling them but they confirmed that they are inanimate objects and therefore this was not possible.  So far I accept this reasoning.
Look at it!  This is seriously 'I am not a happy plant' territory.  
Withering - it is withering in front of my eyes.  I have kept it watered but not too much, but I think my big (and clearly unforgivable) mistake was that I put it in the conservatory.  My conservatory is quite cold and Tibouchina need to stay fairly warm.  Once I saw that the leaves were coming off I brought it into the lounge which is kept a lot warmer than the conservatory, but is it too late?
I am hoping not, I think that there are encouraging signs that it will recover.  So if you could all keep your fingers crossed for it I would be very grateful (and so will the plant).