How do I politely/tactfully say that I make decent money?? How do I get my family to stop?

If I were you I would focus on the job satisfaction part of it rather than thje money side, otherwise you're just playing thier game and it will go on and on and they will think that they way they view things is ok. All it should take is you telling them honestly that your job is ace, and if they come up with a load of arguments about why it isn't then talk them into a corner and say "why is this not ok? Why is loving my job not ok? Why is being able to afford to live not ok? Why is your life more worthy then mine? (helps if you can insert an example about how their life is not as great as yours, eg, you moan about your job all the time, you hate your boss while I love mine, you should be jealous of me, blah blah). Keep remembering that as an adult you do not have to justify yourself to them. You are equals now, all grown ups, all in control of your own lives, and you should not be spoken to like some child who is not fulfilling their wishes. Take charge, be an adult and tell them their behaviour is unacceptable and that you want an apology!