Just tell her that you want to take a couple of weeks apart(not with other people, just apart.) Give each of you some time to hang with friends and let you be yourself for awhile. It's been my experience that and individual can kinda lose their individuality in a long relationship and a vacation from the relationship can really shake the cob webs out and clear the air. Also give you some time to reflect on where you are headed in life and see if you are happy with it.
Let us know how it goes! :thumbup: