A day off

Please correct my writing.

I'm am usually off work on Sundays. I'm  doing a usually volunteer  activity while a day during my off days. A friend was upset because another friend shifted her responsibility to her suddenly, so she had to prepare for an event by this Friday. I was off to go am going to help her this Sunday. She prepared a little by herself much before we met. Therefore we finished this job and so we were able to get out early because of her. I was lucky to have another the free time.

Thank you for reading.

A day off

Please correct my writing.

I'm usually off work Sundays. I'm doing a volunteer activity while I have the day off. A friend of mine was upset because another friend shifted her responsibility to her suddenly, so she had to prepare for an event by this Friday. I was off to go to help her this Sunday. (Either you should say "next Friday" or "last Sunday", or possibly "this coming Friday", because the dates are confusing me in this sentence and imply that her project is 2 days late if you're helping her on Sunday) She prepared a little by herself before we met. Therefore we finished this job early because of her. I was lucky to have another more free time.

Thank you for reading.