"I love you" vs. "Love you"

I am in even less control of my emotions than I usually am, and the difference made my cold, sleepless night into a physically ill morning. Once might not have bothered me if the next time I was reassured, but twice has sent me into an insecure panic and has what will eventually not be a little stuck on my mind. I knew it would hurt, but there's not even anything behind this. I think there's a difference, and I hope it's not prompted by anything.