upset & frustrated...

My son is almost 3 months old .. but according to his adjusted age he was one month yesterday. I try and play with him through out the day .. he'll be fine for about 5 min & then start freaking out ... until I pick him up and then he'll come down. I don't want him to get used to me hiding him all the time ... bc unfortunately I have to go back to work soon. And I won't always be here .. does anyone else have this problem when they try and play with there baby? How can I get him to be happy and not cry all the time??