Baby girl will sleep in the carseat but not in her crib?

My daughter used to eat then pass out as soon as you put her in bed. But the first time i took her to her first Dr's appointment and she met the car seat it was like love at first sight. Now she has a hard time sleeping in the crib but knocks out as soon as shes put in that car seat. What can i do? Ive tried swaddling her but that only works for so long.