Simply do things. You don't have to get all fuzzy and googly eyed again, just start to do some of those things that have been sitting in the romantic place in your brain, hybernating for the last 6 months. Every day try to remember who you're doing it for and why it matters. I promise that soon enough you will remember why you spent so much time and effort getting his/her heart in the first place. Caring is contagious, so as a plus, you may even see a little kickback from your thoughtfulness. The Lull cannot end soon enough people, so go get your Significant Other back and stop being so damn stupid.