Fussy babies

My baby is so used to sleeping on top of me and that’s the only way she’s literally will sleep . Once I put her down she cry’s and fusses till I pick her up again . This is the same as a throughout the day thing . She’s just used to being held !!! Ughh, I need your guys help . What are some tips or advice you can give me to over come this , should I let her cry it out? HELP!!