I certainly don't have an answer for you, but I wanted you to know that I truly care and will pray for you. Remember, you are probably really exhausted. New babies are stressful, though fun, even if you have a full milk supply. It is hard to make a good decision when you are sleep deprived.
You may be second guessing yourself because you are following Abigail's cue. Remember, she hasn't done the research on breast feeding like her mommy has. She can't possibly know how beneficial just the sucking motions at the breast can be for her ears, etc. Even if she justs gets a few ounces from your breast, nothing can possible replace the way your nipple draws into her mouth.
If you want my two cents...drink lots of water, rest as much as possible (yeah right) and just decide in your mind to take baby steps. Try something different...I read somewhere where you could bandaid the lactaid in place before you start nursing, clamp it to where there is no milk flow until she empties your breast, then unclamp it. You've probably tried everything, but I'm guessing she is too upset by the time you are trying to get the tube in her mouth to cooperate.
I have read many of your posts. You have done such a wonderful job getting ready for Abigail. You have made so many good but difficult choices on her behalf. She is blessed to have you as a mommy.
Keep us posted!