I'm a bit uncomfortable about hearing people tell others what not to feel, sorry
I think telling someone not to feel bad and not to feel guilty - while meant to be supportive ane encouraging, I know - goes against someone's right to feel what they genuinely feel!
It is ok to feel revulsion and still carry on doing something - for love, or because of deciding to let our knowledge (of the positives of bf) overcome a more gut reaction.
I know many women who have stopped bf (because of many reasons) and feel guilty for doing so. It is not up to me or anyone else to tell them not to feel guilty. Of course, guilt may not be the most 'appropriate' response - anger, disappointment, sadness, regret may be a more accurate reaction, as guilt implies self-blame, and women who don't breastfeed have nothing (rationally) to blame themselves for. That doesn't stop them feeling as if it's their fault, though.
I have known women who are scared to voice negative feelings about having stopped bf, because people are just a bit too keen to tell them it doesn't matter, and all that matters is they and their babies are happy....well, to them it does matter, and they are not happy formula feeding, and they have a right to feel ambivalent.
Please, I am not criticising these genuine efforts to support other mothers, which come from the right place in the heart. But lets try and think them through