separation issues

Is it normal to have separation issues from my SO? I've been with him a year and have spent almost everyday with him. We go no longer than 3 days without seeing each other & I know people might judge that, but he is my absolute best friend. He's moving to a different town tomorrow for the better, but I'm having a real hard time with it. I have very bad attachment issues & think it's because so many people have walked out on me. He says he likes how attached I am because he's always reassured of my love for him so I'm not to worried about it. Is it normal to feel so attached?