I have a disc bulge in my back which is making me grumpy too.
Having treatment for it (luckily my girlfriend is a physiotherapist)
I might just be exhausted.
Had an hour sleep in the afternoon yesterday and a good nights sleep last night.
Feel a little better today.
I seem to go in cycles of where I hit a point where I need to start again.
Building myself up day by day until I feel good or great for a longer time each time then collapse.
Is this normal?