I am not sure what type of turtle you have or if you have it indoors or outdoors. We have had numerous turtles that we mostly keep outdoors. Most of our turtles have been land turtles and they usually hibernate in the winter. Some of them will dig in to the ground and we won't see them til Spring, others will just slow down and only come out occasionally. I agree with the other posts about the turtle needing to adapt and also, they do have different personalities. We have had very "friendly" outgoing turtles, but most are shy and withdrawn.
If you have the turtle indoors, do you have a special "reptile lamp?" The turtles that we kept indoors became sick and died, if we did not have a reptile lamp. Or you can take them outside some every day. They need sunlight or they become vitamin deficient. Mine would begin by getting swollen eyes that would eventually swell shut. Hope that is helpful. Good Luck!