help me please

I just recently started dating a guy who I've known for years, but we just got back in contact, he has a daughter she's beautiful and she loves me! But I have a habit, every time I meet someone I like I worry they're going to leave me and/or find someone better... so I act over the top obsessed and so far he says he loves it! But I can find it annoying, I want him to know I really like him (starting to fall deep) but not to the point where he'll find me clingy and annoying. Help?