A: When you tell me you come from a poor family, I know you're referring to finances. But you suffer from another type of poverty: powerlessness. You feel unable to make decisions that will create a better future because you're afraid of how your relatives might respond. This isn't about getting your family to change; it's all on you. I think a lot of the problem is your innate desire to save the day rather than to set limits. I'm not suggesting you become mean or stingy, but you didn't say that your family members are incapable of providing for themselves.
For starters, set a move-out date for your brother, or arrange for him to begin paying his share of the rent. Your soon-to-be sister-in-law also needs to work out a repayment plan with you. How does her wardrobe take precedence over your education? There's no need to give a free ride to these able-bodied adults. As for Mom and Dad, separate their needs from wants. If they require assistance to get by, that's one thing. But you can't afford to get them things that fall into the "wants" category. It's also time to talk to your siblings about how they can help with your parents' essential expenses.
I'd like you to keep a diary in which you record every time someone solicits you for money or you feel the urge to offer. If asked, say you need to check your finances. That will give you time to weigh the request. Unless there's an emergency only you can solve, you are to politely decline. Note how much you didn't give away, and after three months, add up the amount "saved." Let's say it comes to $500—that's $500 you don't have to borrow for graduate school. Or maybe that $500 is the start of your savings account. What would happen if you were to invest $500 every quarter in a Roth IRA account that earned an annualized 8 percent over the next 30 years? You would have nearly $245,000 for retirement, that's what. I think you'll soon see the power that comes from providing for yourself, not just for others.