Сочинение по английскому 60 слов. Можете проверить на ошибки?

Question

Надо было написать письмо, объяснить почему я не пришла на встречу в назначенное время. Вот само сочинение: 
Dear Mary, I'm writting to apologise because I didn't meet you as arranged. Today I had a problem. After school when I was doing my homework, my trainer called me and said, that today will be unplaned training. I couldn't come on this training, because next week will be a big competition. I hadn't time to come, sorry. 
See you soon, 
Yours Julia.

Большое спасибо. )

Сергей Самойлов · Accepted Answer

Dear Mary, I'm writting to apologise because I didn't meet you as arranged. Здесь все правильно. 
 
Today I've had ( Present Perfect показано, день не закончился, и связь с настоящим очевидна) a problem. After school when I was doing my homework, my coach called me and said that we were going (согласование времен) to have an unscheduled practice. 
I couldn't attendI this practice (я не могла пойти или не могла не пойти? тогда I couldn't but go to), because next week there will be a big competition. I had no time to come, sorry. 
See you soon, 
Yours Julia.

Анастасия Афанасьева · Answer

Dear Mary, 
 
I am writing to you to apologize because I did not meet you how it was arranged. Today I've had a problem. After a school while I was doing my homework, my coach had called me and said that today we will have unscheduled training. I needed to go on that training because next week I will compete in a big competition. So, I did not have time to meet you. Sorry. 
 
See you soon, 
Yours Julia