I feel like I've grown out of my relationship, should I break up with my partner?

my partner and I have been dating since we were 15/16, we are now both 18, she's in uni, im still in high school and Im moving to a different state next year.

Overall I feel like I have grown a lot as person (not saying she hasnt), and I just feel like we are growing out of each other. Dont get me wrong, I love her a lot, and theres nothing particularly wrong or toxic, but I feel its best for us both to move on, but I also dont know if Im just making it all up in my head.

I havent brought this up to her yet because I dont want her to get offended or take it the wrong way as I don't know if breaking up with her actually is the answer or not.

I feel like me thinking about breaking up is a sign enough that i should just rip the bandaid off, however im scared that if i make a rash decision ill regret it later.

My friend suggested being open but im unsure.

Thanks