N.P.
It could be a phase. My first child went through it at 6 months. He got better with time. And now, at 18 months, he's going through another bout of separation anxiety.
My 4 month old is starting to get cranky when he can't see me also... so I guess this phase is creeping up on him too.
That's just one idea. My baby liked to be held all the time.. pretty much until he crawled... :) Fun stuff!