I think it's great. My only criticism is that if anyone is looking closely at the letter, it looks as though you wrote "I cat seem to get over that feeling...." At the top of the second page. I personally like it. More real with misspelled words, I think. Awesome work making up things for it to sound like real love letters. Good job.
It turned out more than just good - it's fantastic. I like how you chose to put an old-fashioned pen instead of a modern pen. The colors you choose are always perfect for the artwork. ^^ This is no exception.