I am also a Junior in high school and I have finally made a solid decision on what a want to be(psychiatrist), but I don't know what it takes and I really need to know because my time is very limited. I will be in college in just two years and I feel like I need to get everything together as soon as possible. I was going insane because I was looking at all the careers I was interested in and when I saw the requirments a was crushed time after time after time so I just need to know what I need to do to become to do this. I dont care what the requirments are. I will reach them whatever they are. This is it for me.
As a junior in high school, I would not worry about requirements to be a psychiatrist, aside from the need to do well enough to get into a decent college. You probably want to make sure you complete the basic science classes and math courses in high school but you don't need to have done too much more.
Once you get started in college, you'll need to make sure you take the required pre-med classes:
1 year general chemistry
1 year organic chemistry
1 year biology
1 year physics
And then around Junior year of college you need to take the MCAT exam. If you did well enough in your courses and on the MCAT, you can get accepted to a medical school. After 4 years of medical school, you'd have to do a 4 year residency program in psychiatry.
As a ujunior in high school, I would not consider your time limited at all. Many people decide part way through college that they want to be a doctor / psychiatrist and you would still have time then to complete all of your requirements.
Additionally, more and more people are deciding to go to medical school later in life, completing the pre-med coursework as night courses while working their current jobs.
Best of luck, and let me know if you have other questions.