Everybody hits a wall once in a while. You think there's nothing left for you to ever write about, but there is. Walk away. Read a book, watch some TV, talk to some friends...maybe even read a newspaper...and surprisingly something will come to you. Someone will say something or you'll read something and voila, it'll be there.
Read other hubs when you're not writing and read other questions on hub pages, there may be ideas there for your to write about. Never give up, its just a dry spell and it will end, I promise.
If you get really, really stuck and think I can help, contact me and I'd be glad to try.