I don't know your mother or your specifics obviously, but I will give you my gut opinion. Your mother seems very manipulative to me. She obviously intended to guilt you into forgiving her. It sounds like she's also managed to blame you for causing problems for her in all of her relationships, and her financial struggles! The problem with that is, it's just absolute bullsh1t. A child is not responsible for their parents relationships or finances.

Reading your post, the story felt very familiar to me. The classic narcissist blames their children (or one child) for all of their problems, they will never be able to see they are wrong in anything. A classic abused child is often full of self-doubt, because out of self-preservation they want to believe their parent is not so bad. Growing up a child relies on their parents for food and shelter, there are psychological mechanisms in place (disassociation for example) that makes abused children often reach the conclusion they are bad and to blame for their abuse vs. facing the very frightening awareness that their parents are in fact too selfish to be able to really care about them. Classic abused children often grows up with low self-esteem feeling bad and damaged as a result, often unable to open up and have close intimate relationships without intense fear that they will be abandoned, since their parent(s) have displayed that they must meet certain criteria to be acceptable, vs. showing unconditional love, which is the healthy secure response.

Your mom won't work on it with you, won't go to therapy, doesn't seem to care about your feelings, seems instead out to make you feel guilty, blames you for all of her personal failures... she sounds like my mom, who is severely mentally ill, and has been running this same pattern of blame, refusing to go to therapy, and gaslighting my whole life. Check this out: http://en.wikipedia.org/wiki/Gaslighting