Hey Jo!
I feel the same way. Some days I'm just anxious and panicky. Other days, well most days anymore, I'm just tired and dragging and feel like I'm floating. Some nights I have a really hard time getting to sleep, other nights I wake up practically every hour. I don't think I've really woke up feeling truly refreshed and rested in years. I seem to always have a headache and get dizzy spells all the time. I know this completely sucks out loud, but it is the anxiety causing you to feel like this. Anxiety / panic really takes a lot out of you physically. So does depression. I've noticed that when I'm in a good mood and having a good day, I feel energized and just plain ol' fashioned good. I haven't felt like that in a few months though.
Exercise helps. I haven't exercised in a few months and I think that's one reason I have been feeling like this so much lately. But, taking a 30 minute walk around the neighborhood every day or on a treadmill if you are unable to leave the house, or even working out with a workout tape helps you feel stronger. Try to exercise and see if that helps. The first couple of weeks will be hard if you haven't worked out in awhile, but start very slow and do more as you feel stronger. I think I need to take my own advice! Crimeny ;p
Oh! By the way, I didn't get a chance to answer another post you had put on here about having a buzzy feeling in your arms and legs. Just wanted to let you know, I get that one also! I get it a lot in my scalp. Any uncomfortable symptom we get will get worse and happen more often the more we pay attention to it. When it happens, try to remind yourself that it is just the anxiety screwing with you again and everything is ok. Once you come to realize that this symptom isn't going to hurt you, it will start to go away. You have to prove to yourself that there is nothing to be afraid of with each symptom as they arise. That really is the only key. Start the program here if you haven't yet, it will teach you how to do this. The program is free and very helpful and informative.
Hang in there! What you're feeling is normal - I promise!