My baby is now 6 months old and she's always been rocked to sleep for her naps. Night time isn't so bad but day time I have to pretty much bounce for 10 minutes to get her to sleep. I'm starting to get a lot of back pain as she naps 3 times a day and getting heavier. Iv tried some light sleep training at 5 months, patting/rubbing back, waiting for her to cry couple minutes then going in picking her up with a shhh to calm her. and it never worked. Do I just persevere? Will she grow out of it one day or do I need to some how train her?