From reading your posts, I doubt seriously that the bf's mothers problem is with you personally, it is with ANY WOMAN who dares to date her darling baby boy. She will continue to find fault and I can almost promise you that the bf will set his ultimate "woman" standards as a model of his mother. I don't there is anything you can change the situation, it is all up to the bf.
Unfortunately the mother and son are a package deal. I wish you the very best of luck. However, if you do hang in there, be kind and respectful and try to get along, eventually she may come around.