Is something wrong?

My little one who is just about 5 months.. is always wanting attention from me and not her toys.. She always needs to be held.. I dont know what to do.. I try setting her alone on the floor with a bunch of toys and she only sits there for not even 5 min then she cries so bad So, i pick her up... try to put her in a bouncer seat she cries right when you set her down same wit the 360 center. What do I do? Its like she is constantly needed something new.. I seen babies who are into things longer than that she is very fugity.. and is this normal? whats wrong? I am trying not to hold her so much and let her play with toys and learn on her own without me being there 24/7.. same with sleeping at night she wont go to bed unless you ley with her- What am i suppose to do? They say to cry it out. What if a baby doesn't cry it out..and goes on and on and on,