Sleep help please!!!

I’m at my witt’s end with my 3rd child. I love her more than anything but her sleep habits are SO exhausting I cry about them everyday. She is 14 weeks (my other too are 3.5 and 1.5). Her first and last nap are in the carrier on me while I run around after the other two. For the 2nd nap I try her bassinet. I follow her wake window- 1.5 hours and do a sleep routine (new diaper, swaddle, sound machine, song). She will not fall asleep- even after 40 minutes of rocking her, patting her, shushing her, she will not fall asleep. She’s crying the whole time so none of my efforts are even comforting her. I finally give in a nurse her after 40 minutes. But then the second I move she wakes up. I am so exhausted from the morning I just need like 10 minutes to myself. My other babies fought sleep but nothing like this. Help please!