I think your letter is exactly what it should be. I don't think its pointing a finger at anybody. I think you stated well how you have taken responsibiity for your thought and actions. I think its a good idea to hand it to her but i really think you should email her because then it proves that you need to see her more then once and if she gets disappointed that you didn't call, then tell her that you don't want to bother her or the fact that she seems to busy to fit you in lately. Great job on the letter!!! I hope this gave your mind some rest.