third year of high school

[bosun]

Can I say third year of high school in the following sentence?

When I was in( or on) the third year student in high school, I only had to study for a university entrance exam. If I were given the power to change one thing in my life, I would change my third year life of high school.

[2006]

Can I say third year of high school in the following sentence?

When I was in the third year student of high school, I only had to study for a university entrance exam. If I were given the power to change one thing in my life, I would change my third year of high school.

2006