Lethargy

Ok, this one will be short. It is more of a question. I struggle with lethargy sometimes. I have lots to do but absolutely no drive to do it. Sometimes it is being physically tired, sometimes it is mental exhaustion, sometimes it is just plain procrastination. I think sometimes it is even being overwhelmed at the sheer amount of stuff I have to do and it is fretting over how to get started. There are days when this is nearly incapacitating. Do any of you struggle with this and if so, how do you get over it?