Dear имя друга,
Thank you for your letter. It is so great to hear from you again. Sorry I haven't written for so long.
In your letter you ask advice.In my opinion you should try to take exams in next year again.You should not give up, you should fight for your better future.
I have a dream. I would like to be a journalist, because this job is very interesting and exciting. Journalism is very important today. Without journalist peaple can not learn news, find advice and other interesting information.
I think it is right for me, because this job has a lot of advantages. One of them is travelling. Journalists travel a lot. They can see all the world, learn how live other people in different countries, cities, their values,traditional. They have widespread knowledge of the world.
Well, I'd better go now to do my homework.Hope to hear from you soon.
Best wishes,
Свое имя (не ставь точку)
Надеюсь, что помогла тебе