Ok Beth, We have a long way to go. So Hang in there.
First off. If your using window light don't mix it other light source. unless you can filter the lights to match. I'll thinking the brown spots you were talking about are coming from mixing day light with tungsten light. ( not in the shot shown). Are the room light on?
Look at my levels tut again. I think on the first page some where. I talked a lot about filters. You would need a 81C filter over your lens for the deep soft blue day light. Or heavy over casted sky.
Now lets look at you photo to answer your question about eye droppers.
Notice the high light in the middle of the circle. Thats the white point. Now look at the background, its a lot darker. By clicking on the background with the eye dropper your throwing away a ton of information that was needed in the bead. Thats why it went so bright white. Just for fun try this. Make three copies of this image. In levels use the white point dropper on that high light and see what happens. On the second image click on the background at the top of the frame. On the third click on the background below the bead. This won't help your photo. But you will see how the eye droppers throw information away based on the tone you click it on. And thats why I say don't you them.
I played with your photo and that the best I could do. But had to cut the background out. could not save that at all.
So lets get your photography closer. Work on getting your lighting consistent and balance. and your exposure correct.
Scott