Jenn...

6 lbs. in a week IS a lot for someone who starts at 135 lbs; that's 5% of her total body weight where your 8 pounds the first week was 2% of your total body weight. That's still a very good loss for your first week, but you also have to look at where the person started and percentages when you compare numbers.
I think Kamila understands that eating just protein is not a wise way to pursue losing weight, especially when I read her last post above.

Kamila...

I'd still like to seriously encourage you to re-examine your goal weight. At the height you are, that is far too low even for someone with a very small frame. Trying to get too thin will only come at the expense of losing muscle tissue, even if you are eating plenty of protein and this is not something that you want to do. Less muscle means that your body will burn less fat and need less calories and I don't honesly believe that you want to spend the rest of your life having to eat a very low calorie diet just to maintain. Once most of the fat is gone, your body has to get it's energy from someplace, especially if it is not getting enough calories. If you are just feeling a bit flabby, then weight resistance training will help you tone up and look long and lean; losing more weight isn't the answer there.
Please reconsider how much weight you think you need to lose or consult a health care professional before you lose too much more.