I understand what you are going through, I thought most of my breast feeding problems would disappear after my milk came in and they latched alright. But I was wrong.
I have twins that are 14 months old and they were majorly breastfed. At 6 months, one of them stopped latching because the bottle was easier for her and she was lazy. So at that point, their father and I, devoted ourselves and took the bottles away all together. She definitely went back to the breast when she was hungry. Make sure to try slow flow nipples.
Side note: (Which is weird and talk to your ped.s about it!!!) Try doing formula at her bottle feed. It tastes worse, but she gets what she needs, and then, in theory, she might really treasure that mommie milk.
At about 8 months, the girls would get so distracted while feeding. They would start poking each other in the face and ignore me all together. I would have to sit there for an hour. They would be on and off. I felt like a cow at the pasteurizing plant.
Anyway, good luck!!! You are doing a great job!!! Eight months of milk, that is awesome.