How do I become a dietitian/ nutritionist? (What steps do I take?)?

For any career, I suggest something you have a passion about.
From what you say, it has become an interest and perhaps a passion, so it would be a good choice.

Look ahead to a college you might want to graduate from for nutrition, and look at what is necessary courses you'll need.

Oh - get Dr. Fuhrman's book about eating only the most nutritious stuff. This might be a great basic book if you move into this field. It's a great diet - you might try it yourself. It's greens and beans and some fruit. Plenty to eat and it's all pretty cheap.

At 16 you have to finish high school - take some math and chemistry. And then go onto the University in Pre-med. From there you can dodge anyway that interests you.

BUT... the most important thing is to keep eating well and staying off the JUNK food.

Yes. Keep some before and after pix. When you start looking at colleges, find out which ones have nutritionist. Maybe a little med school would help. Very noble profession!!