I don't think it's your eight-character incompatibility, but your family conditions. A pessimistic and despised Taurus girl must have the most suitable material foundation for her, otherwise she will feel insecure.
Think about it, as a mother, how can I make my daughter suffer? So you should try to make your life more stable, impress the girl's mother with sincerity, and make her feel that it is right to entrust you to you.