New relationships.

I'm a young woman who's never had a real relationship. By that I mean anything longer than 4 months, and actual boyfriends for more than 1 month. 
I've started seeing someone I really truly like, been spending a lot of time together at his place, like 3 days at a time, and it's really nice. He just asked me to spend the week with him and we've only been seeing each other for 2 weeks now. I'm not used to seeing someone this often. I usually get to see guys once a week or less. 
I feel so anxious when I leave. Like, I worry something's gonna happen to him or I worry that he's gonna change from being the sweetest guy to one of the many disgusting guys I've dated in the past. I feel as though I'm TOO happy. That its gonna be ripped away from me like it always has been. Is this normal to feel this way?