Hi Elliep, Its too warm in your Lounge, I brought one in a few winters ago and it done the same as yours then it went crispy and died :( An unheated Conservatory or greenhouse would be better..
when i had one planted in my garden (the last 2 winters killed it) I would tie up the leave's as thats where the snow does'e the damage, in the heart of the leave's..
you could tie it up and put it against the outside wall of your house (warmer) and pray we dont get another winter like the last 2..

You've not filled in your profile to say whereabouts in the country you are so it'll be difficult for people to advise you specifically.

Apart from the last (cold) winter they've survived winters outside just fine, it was last years minus 12's in this region that killed the exposed ones.

If you too are in the south or south west yours may well be perfectly alright left outside over winter, if you're in Ydd's area it'd need protection - not necessarily from the cold but the frost.
Definately don't take it indoors though, they're not that tender.