I need your help.

This letter was sent by Disney artist Kay Nielsen to a friend on December 1940. As you can see, his handwritting is a real challenge.

Here is my current interpretation of the text:

[We are all right, only we are deadly tired – now the dentist is over – it was a horror and [dominated] all my weekends for three months. Tomorrow I am to have the first conference on The Swan of Tuonela. I have got Bill [Wallett] back and he is going to work with me on that music – and it is wonderful music too – only I wished I was not quite so tired. I have done too much and worked too hard on the little [XXX] but I hope this will be good – it might too. I seem to be the sombre sector at that place. God knows whether they really like it – and I have yet to hear anything about the new contract. Strange we must admit.]

Could you help me figure out the XXX? Am I making some mistakes on some other words?

[UPDATE: As many of you noted, the missing word is "mermaid". This now appears so obvious that I want to kick myself ;-)] 

[And here is the corrected text thanks to several of you:

"We are all right, only we are deadly tired—now the dentist is over—it was a hard one—it ruined all my weekends for three months. Tomorrow I am to have the first conference on The Swan of Tuonela. I have got Bill [Wallett] back, and he is going to work with me on that music—and it is wonderful music too—only I wish I was not quite so tired. I have done too much—or worked too hard on The Little Mermaid. But I hope this will be good—it ought to. I seem to be the sombre note at that place. God knows whether they really like it—and I have not yet heard anything about the new contract. Strange one must admit."]