I was also gonna suggest that the snake is going into shed. When their scales get dull and their eyes cloudy that means that a shed is coming shortly.
Also, from the pic you have besides that the cage is all wrong you need to put TWO hides in the tank, giving him or her a choice of a warm or a cool hide spot. BP's love to feel secure and able to touch the hide walls on all sides of them. And it seems you have the log on top of some kind of climbing tree? If so get that flat on the floor of the tank so that it can be more of a hide.
Get rid of the net tank. Get a UTH with a thermostat( VERY important) set it to about 93. And the humidity needs to be about 70. Even more so during shed periods. Either pick up a glass fish tank or you can go with a sterilite container. either way will work. At this point you snake does not have the proper living conditions.