7 lbs. is nothing to scoff at for 2 weeks. Keep it up and don't obsess about the water. Just try to turn it into a routine you do. Kinda like some people take coffee breaks...take a water break!
What kind of exercise routine are you on? You may have said before and I just missed it, if so I am sorry.
Keep up the good work, just think those are 7 lbs. that hopefully you will not have to worry about again!
Later,
Dax