I can get 20+ hours literally and still be tired. I've been trying to stay up all day so I can do things, but it's hard. All I can think about is sleep. I get dizzy from being so tired. I had blood work but everything is fine except my cholesterol. I have tachycardia and on a beta blocker and Wellbutrin and Lexapro, but I've been taking them for a few months with no problems. It's been more recent I noticed being this way. But I'm trying to make a better schedule and maybe that will help.