Well done on your loss BiO that is a great effort. That's 18kgs to us metric people.
I always find it easier to exercise when it is warmer as no forcing myself to go out in the cold. If you are used to exercising indoors, maybe take it outside with brisk walking or jogging. It's lovely smelling the fresh air and the sights and sounds of a Spring day. We are in Autumn here but I am already hanging out for Spring 6 months away.