My schedule is very tight this week.

[Silverobama]

My friend, a few weeks ago, told me that he could give a book about professional medicine and yesterday (Monday) he asked me to get the book, I said I couldn't meet him because the whole week for me would be very busy, I said to him "My schedule is very tight this week".

Is my sentence natural?

 

[emsr2d2]

My friend, a few weeks ago, told me that he could give me a book about professional medicine and yesterday (Monday) he asked me to come and get the book.

See above.

I said I couldn't meet him this week because the whole week for me I would be very busy. I said to him "My schedule is very tight this week".

Is my sentence natural?

It's OK but it's a bit formal. I'd expect to hear something like that from a professional person who's been asked to have a meeting but they're too busy. In your situation, I'd just say "Sorry, I'm really busy this week so I'll have to collect it some other time".