Silicone Preference

Leah • 32, Accountant.
I'm FTM & have been trying to get my LO to latch since birth. 
He initially couldn't do it because he had an almost 80% tongue tie so I started expressing & bottle feeding. 
His tongue tie got cut @ 1 week 5 days. 
I stopped expressing & started using a nipple shield to get him used to the flow from them breast, I occasionally take the shield off and try to get him to latch on, which he does but only for about 5-10 seconds after which time he screams into my boob until I put the shield back on & he starts feeding again.
Anyone else had an issue like this? How do I get him to latch onto me instead if the shield? He is literally just not interested in my boob at all without it? I need help!