Could someone check my writing please?

I am an IELTS candidate and in the exam I will be judged according these points:
• answer the question without straying from the topic
• write in a way which allows your reader to follow your ideas
• use English grammar and syntax accurately
• use appropriate language in terms of register, style and content

I'd be grateful if someone could check my writing, punctuations and tell me whether I've covered these points or not. Thanks a lot.

Task: a family member is coming to stay with you. He/she will be arriving by train in the morning, but you won't be home until the evening.
Write a letter to your relative. In your letter:
• Explain arrangements you have made fro them to have keys and get to the house.
• Tell your relative how to get from the train station to the house.
• Say when you will be home and suggest what you could do together that evening.

Answer:
Dear,.......
I'm very excited that we are going to spend the weekend together. It has been such a long time since we have met! However, I regret to inform you that I won't be able to meet you at the station as soon as you arrive. The reason for that is I won't be able to leave work until 2 hours after your train arrives as I have a deadline to meet.

I am afraid that you will have to take a taxi to my apartment by yourself. It is on 6th avenue at Main Street. It is the second building on the right, 5th floor. You will find the key of my apartment with my neighbor John who lives in the opposite apartment.

When you arrive, make yourself home and get some sleep. It won't be long until I arrive. I was thinking that we can go to the rock concert at the stadium tonight as I have two free tickets. However, if you are not in the mood for concerts we can go see a movie. Just keep safe and I will be seeing you tonight.
Yours Sincerely, ......