I can understand why this upsets you. I can also understand your relatives' point of view. Doing business with family can be difficult and is not something everyone is comfortable with. It would have been nice if they had at least given you the chance to get a referral fee here but they didn't and how you choose to react to this will tell them a great deal about your professionalism and may determine whether or not they refer friends/family to you in the future.
I see something in your note that you may want to work on going forward: You're very focused on yourself here when you need to be focused on your customers' needs. No one in your life ever owes you a listing, especially not just because you need money. If you're getting business, it should be because you're a hard-working, customer-focused, problem solving, aggressive professional who is determined to get your clients the best possible outcome.