Sweetie, everything will be ok!
So what's the worst case senerio? That Violet is completely deaf? Well then what? You learn sign language......Which in and of itself is a beautiful, poetic language, and very expressive! It may be harder for an adult to just pick it up, but you will!!!!
I know right now it just seems so overwhelming, I just wanted to send you big hugs...it's hard when we come to realize that our child may not be "perfect" by society standards, but that doesn't mean she isn't perfect to you. She was given to you to care for, to love, to cherish...you are doing that! She was perfectly designed for your family, she is the perfect addition to you!
My best friend is deaf, we've known eachother for a long time. I think the only mistake her parents made was making her feel as if she were different, she hated that. She just wanted to be the same. Her parents also didn't learn much sign language, just enough to barely get by...I know more sign than they do.
Also, there is another deaf mama here on the boards, if you do find out that Violet is deaf, it might help to get her perspective on the deaf community and the hurdles she had to overcome growing up deaf.
Oh, and most children aren't diagnosed with hearing loss until they are 2 or 3 (sometimes older) a lot of parents would have missed it. It wasn't something you were actively looking for....of course you missed it. That doesn't make you a less attatched mama