My 8 month is driving me crazy!?

He fights sleep like a wild man, I mean it is like he has colic, he is crying %70 of his waking life, I know he isnt in pain bc as soon as I pick him up he stops... most of the time. He constantly wanting me to hold him and I seriously mean 24/7!!! Any good ideas for calming a baby o sleep, I have tried reading, singing ect. also any ideas for a baby who HAS to be with mommy ALL the time?