Nipple shield question/ getting baby to breast from bottle

Currently have a five week old baby who refuses to latch. Started to pump around day three and give bottles due to feeling like the baby wasn’t getting enough. Looking back, I’m pretty sure he was. Now we have a bottle preference and I am trying to get him back to breast.

I’ve tried five or six different nipple shields and he will latch on a shield here and there, but I feel like there’s a transfer issue with the shield. For those of you who have a slow letdown or maybe a slower flow do you find that there is a transfer issue with a nipple shield? I know it’s not as big of an issue for those who have a quick letdown or super fast flow. I’m only assuming I have a slow letdown in slow flow because when I pump it takes me 25 to 30 minutes to empty.

Any other advice welcome for getting baby back to breast!