Have a five month DS, and he's my first with all this parenting stuff being completely new to me, so please be kind to me if I'm asking something completely stupid! 
Is it normal to feel completely exasperated and fed up with your baby? I love him, and he's the sweetest angel in the world when he's just woken up in the morning but we both seem utterly fed up with each other at the end of the afternoon, before bath and bed.
After his afternoon nap, his crankiness and frustration at not being able to move build into a constant grizzle and I'm then forced into giving him my complete undivided attention (singing, dancing, playing games), until the time thankfully comes when I can give him his milk, a bit of fruit purée, bath and then off to bed. By this time I'm skipping down the stairs after he's in bed.
Is this normal? Pre kids I had this vision of blissful motherhood but I just seem pretty fed up a lot of the time.