I have the Pidgeon brand nipple shields but never managed to succesfully breastfeed with these (I bought them due to extremely sore boobies thanks to bubby's 4-hour long cluster feeds). Perhaps I just don't have long nipples, but I found that my nipples were too short for the shields.

Joining the ABA is a great idea and a way to empower yourself to have the best shot at breastfeeding that you can have. Hope your journey is successful!