SuperB...you say in one post you have a child who lives with your parents and then in the next post you say you know the sacrifices you have to make having children.
If your parents are raising your daughter you don't know how difficult it is...you're not dealing with the day to day problems that are part of parenting (and believe me it's endless).
I think you are indebted to your mother for the continuing sacrifice she's making for you. Maybe her attitude towards you is as result of feeling unappreciated by you. At her age she should have raised her kids and look forward to a peaceful retirement, instead she has another 16 yrs of raising YOUR kid.
Give her a break, suck it up and apologise to her for your behaviour. Why should she sacrifice her twilight years for a "mistake" you made?