please help

I’m 17, my boyfriend and i have been dating for almost 5 months now. I love him a lot, we are super compatible, great at communication, our families love each other, etc. But, i can’t help but feel tied down in this relationship. Is that normal? I feel tied down even though he’s the perfect one for me, and i can very easily see a future with him, which i haven’t been able to see with anyone else before. I know i would marry him and create a life together if i could, so why do i feel so tied down? Why do i feel like this relationship is the epitome of my experiences with love, sex, intimacy, etc? He was my first so i don’t know if thag has anything to do with it. i don’t know if that makes sense!!! I almost wish i could have met him later in life. Does anyone know what this means?