i need help i’m 16M and my girlfriend 16/F i constantly feel like she’s going to leave me how can i stop feeling so scared?

it’s constantly me sending a message waiting for 2 hours for a reply which is very short and doesn’t have any detail at all like people call dry but i just can’t i know that we are both extremely young but it is so much deeper than that this is my first serious relationship and i cannot deal with being scared that she would just find someone better than me . all i want in my life is to feel loved