Hi Susan,
I'm really sorry I didn't go to the concert with you last week. I was sick and had a fever. Not only that, but my head hurt really awful, and I couldn't even walk. All day I was sleeping or just laying on my bed. But anyway, thanks for these photos and videos you sent me. They were great! I was really having fun watching them. I really regret that I couldn't come. Anyway, I hope we can go together next time.
Hope to see you soon.
Write back, XYZ
Jeśli potrzeba tłumaczenia, to mogę je dodać. :)