Have you been tested for ross river virus? I had very similar symptoms just over two years ago (so tired I even found it hard to drive as I couldn't be trusted to stay awake!). Anyway if you haven't it could be worth checking. Not much you can do if it is and the best advice I was given was to keep going and keep my immune system up as much as possible. Even though it just had to be ridden out and I will occasionally still get flare ups, knowing made me feel better and that it wasn't all just in my head.