Sadly, finishing a glass of milk, eating whatever is on the plate, and not being glued to the television set is no more the way to go to please our parents. We are that class of people who are teetering between major life goals and the burden of expectations that we carry from our forefathers. But having a vision for your own life distinct from what your parents have chosen need not be a burden to weigh you down. And there's absolutely no need to beat yourself up about it.
Your choice to be a writer, director, or musician is not something your parents might see as a career. Know that they are weighing the options through the same lens through which they have lived their own lives. The very famous 'but in our day' stories will talk about the hardships they went through to lead a 'settled' life, which your college degree promises. You might not be on the same page now, but if you follow their plans for you - you might never get where you want to be. Wouldn't you rather make something out of yourself, and be happy about it, rather than just skim through life on the safe territory?
If you have the balls to follow your passion, I'd say go ahead, do it. If it ends in failure, you'll at least be happy you tried. The thing about following your desires mercilessly, is that you own up to all your decisions. Rather than living the life your parents planned, and blaming them if things don't work out, wouldn't you be happier knowing that you gave it your all and tried?
It's okay to disappoint your parents, if that's for the greater good.
Don't mean to sound like a douche when I say that, but it really is how it is. They might keep asking you to make use of the college degree you have, but a career in computer science is not what'll get you the fame of the most celebrated artist- which happens to be the thing you want. The world is your oyster, my friend. You can choose to be a magician with colours and give them the chance to be proud of things they never expected, or...well the world is your oyster.
It's not as if they don't trust you, they just look at things from a different worldview.
There might be a tiny warrior, raging a war in your head about your choice to disappoint the people who mean the most to you, because they should be okay with the choices you make for your life. The expectation is not wrong, but a little unrealistic, considering it's from people who are emotionally unavailable. Our parents are still looking at things from their worldview. Don't judge them, it's their understanding of life. It does not mean they don't trust you.
Never, ever, ever blame yourself for doing them wrong, you haven't.
Expectations are not lived up to when people don't get what they want. Your parents had a series of settled things planned for you that you chose to do in a different way. We're on a different page than where our parents are when it comes to avenues and options. You might just know how to make a certain something work out for you, that'll look far-fetched to our parents. It's not your fault.
You both want your happiness, just in different ways.
Let this be your bone of contention, both you and them want the same thing, your happiness. You both want a better future, and a good life for you. The only little deviation lies in the means. Where they want you to go down the beaten road, you want to spread your wings and fly. Even if they don't understand right now, chances are high that they'll come around. So the little disappointment you give them now, might chart out a happier future for all.
With a realistic game plan, your own validation, and your own expectations, you could go a long way. There's no need to be guilty to choose a different path, but please try and show them that sometimes, you might just get something better when you do things that are unexpected of you.