Hello! I'm sorry to hear of the hurdles you've been faced with so far but I applaud your tenacity!
Both my boys were on nipple shields in the beginning. My tricks to wean off were 1. Nurse before they really got frantic, i found they were a little more patient with me if they weren't ravenous. 2. I put ice on my nips to get them harder and easier to latch on to. 3. The side laying position is ultimately how I got both back to he breast. They're both stubborn and still dont like being overtly directed in that position I could lead them to a proper latch without holding their head in a way that pissed them off and finally, dream feeding in their sleep (also how I got #1 back to he breast after two nursing strikes). When they are drowsy and rooting around I'd do the side lying position and get them on the breast in their sleep so they didn't really notice he difference.