LO doesn't want to latch 😭. What can I do?

Anyone got advise for this please? My LO hasn't stopped latching for a few weeks now. I mainly express pump and latch once a day for about the first 3 months. But after that, she suddenly decided to reject my nipples totally. She only takes it when with nipple shield. Yes I know, it's probably nipple confusion. So now I'm fully express pumping. But I wish to latch again, and knowing that it will help increase the supply. My supply has been stagnant, no matter what I take or do, it doesn't increase. Seems like really need to latch latch latch. LO is now 5.5 months. Any one have suggestions on how to get her to latch again please?