Got broken up with by my first girlfriend after 2.5 years and I’m struggling

I (15M) just got broken up with by my first girlfriend (14F) after 2.5 years of being together and I’m really struggling right now. This was my first relationship and the first girl I ever had a romantic connection with. It happened very recently and I’ve been feeling really overwhelmed and emotional.

I still have to see her at school every day, and I’m not sure how to handle that or how to start moving on.

I’m mostly just looking for advice from people who’ve been through something similar, what actually helped you get through it?