How do you get over someone you still love?

What you're after here is the old classic: "It's not you, it's me" exit strategy.

i was going to suggest that :-)

"i can't stop lying to you so i have to end it now instead of dragging it out, it's the best thing for both of us"

"we have grown apart"

"we are kidding ourselves that things are great between us"

"why prolong a dying relationship when we both know it's not going anywhere"

"i'm bored of this shit and i want out. cos frankly the idea of spending another year with you gives me the fear"

feel free to use any of the above.