Why did it have to end when i loved him so much?

i felt so loved and i really did love him so much. i’ve had people like me before but it never became something serious. then i met him and somehow i just knew. in my head i kept thinking “i want it to be him so badly.”
i grew up in a catholic family but i wasn’t really religious. still i found myself praying and asking the heavens for him. i prayed so hard because i wanted him to be the person i ended up with. i really wanted it to be him.
he was my first serious relationship. i still remember how happy i felt when i finally became his girlfriend after months of talking. i felt so connected to him. we were committed we were serious and i truly loved what we had.
then we had a fight. it started as something small but somehow it turned into something much bigger. it lasted for a month. during that time we still saw each other went on dates and tried to act normal. i think we both saw things falling apart but somewhere along the way we started wanting things from each other that we couldn’t give.
we understood each other less and less.
when we finally broke up i completely fell apart. i cried so much. i felt lost sad and honestly like i wasn’t myself anymore. it was one of the hardest things i’ve ever felt.
i’ve accepted that it’s over but i still miss him. it’s even harder because we share the same classes and i have to see him often.
i just want to know how to move forward. i want to feel free again. i want to be happy again. he was the first person i ever loved this deeply the first person i truly wanted things to work with.