[quteasabutton]

you'd be better off as friends. don't stay in the relationship just to use her/her dad for a discount, that'll make you feel even worse in the end. be there to support her and try and help her realize that she's an awesome girl and that you care about her. try and find a girl that will suit you better too. do stuff to make sure you don't push your friend over the edge, be sensitive but don't compromise yourself just because of her problems.