Why did he give up on us after 2.5 years?

my boyfriend and i have been together for almost 2.5 years and recently he told me something i still can’t fully process. we’ve been doing long distance through college for the last two academic years and while it was hard i genuinely thought we were making it work. we talked so much about the future even though we knew our careers and lives might eventually take us in different directions.
a few days ago he told me he doesn’t really see a future for us anymore. he said he feels burnt out from school and life and like he can’t give me the time or energy i deserve. he admitted he’s been getting more irritated and short tempered and he’s scared the relationship will eventually become unhealthy if he keeps forcing himself through it. the hardest part is that we had just seen each other for the first time in months after his semester ended and everything felt normal to me. later that same night he texted me saying he hoped seeing me again would make his feelings come back stronger but it didn’t change anything for him.
he kept saying i didn’t do anything wrong and neither did he. he says he still loves me but he’s exhausted and doesn’t want to keep doing this anymore.
i honestly don’t know how to process going from planning a future with someone to suddenly imagining life without them in it at all. we were literally making summer plans and talking about how we’d see each other more once i transferred schools. he also made it clear he doesn’t believe in breaks or staying friends after a breakup. he wants complete no contact unfollowing each other all of it.
i know i can’t beg someone to stay when they’ve already mentally checked out but i also don’t know how to just accept that this huge part of my life is over. i keep wondering why i wasn’t enough for him to keep trying even though part of me knows love alone doesn’t fix burnout or distance. maybe i sound dramatic because we’re young but right now i don’t care about eventually meeting someone else someday. i just want this pain to stop.