Blue tit won’t fly

I have a new conservatory and I was taking shopping in when I saw a blue tit lying on the ground. I suspect it must have hit the window.

It was conscious and breathing heavily but was not walking/flying. 

I put it in a ventilated dark box and left outside under cover from the rain. It’s responded to me giving it water but will not move, I’m worried it’s maybe paralysed but not sure because it can move its head around and still breathing. 

is there anything I can do? Or is it just a waiting game…