First of all, congrats on 7 days. Thats a great achievement in itself. Everyone experiences detox differently, but I can tell you from my experience of withdrawing from percocet that the second week was in some ways harder than the first week. I only say that because most of the physical W/D symptoms had subsided, but the mental malaise still lingered. You have to fight through some of the depression/sadness that you will experience. I felt empty without pills during the second week. But believe it or not, it faded away quickly.
Things started to really turn for me around day 15 or day 16. I'm only on day 18 now, but I feel infinitely better than I did just a week ago.
Hang in there, better days are ahead.
Welcome to the forum. You are just about through the worst of it. It will steadily get better here on out. Take a look at the Health Pages here.
http://www.medhelp.org/health_pages/list?cid=66
Read up on your addiction and know it will always have the best of you. Never take it's power over you for granted. You can beat this but if you get cocky or arrogant, I guarantee it will bite you. Good going! You have taken one of the best steps you can do by quitting!