Choosing a major

I finished my two first years of university studies so next year, I am starting with my major. I didn't pass all my subjects because I had to eliminate one of them, electromagnetism. Anyway, I had enough credits to choose my major, and I chose geology. It wasn't a difficult decision for me because I had already decided it when I was in the high school. Most of my friends have also chosen their majors already.
I'm very excited with to finally start my studies study of geology, and I hope this will be a great year.

Great job! The changes are just to help you sound more native.