Yes. One of the big mistakes I see people making on here over and over and over is when they talk about their spouse or lover having "low self esteem"...
When a person has low self esteem, that usually means that they don't think much of themself.
So, if they don't think highly about their own self, and then they find someone who DOES like them, the person with low self esteem secretly thinks.."if I don't even like myself, then there MUST be something wrong with the person who does like me (in your case it is BigDM)
You are actually hurting your own chances by hanging in there and trying to show her how much you care. She believes there is something wrong with you because she doesn't even like herself, so how can YOU like her if she doesn't like herself? You must be weird or have problems if you can like HER, since she doesn't even like herself...
You answer is to go out and find someone else and leave her alone and act like you DO NOT like her. You will then be agreeing with her own self assessment. This will make her want you again when you reject her.