Am I overreacting?

I’ve been with this guy for years, we’ve been through a lot together. He says he cares about me a lot, and I believe him. But when I asked him if he was in love he told me no. I feel really sad about this. And I told him that I’m sad about it, and he told me he wouldn’t lie to me, and that it’s just how he feels and he can’t change that. What do you think? I just feel so heartbroken because I’ve dedicated my life to this person for the last four years, and I’ve done everything for him. And just to put it out there, he does things for me as well, he’s not cheating or lying to me, but I just feel like him not being in love with me is so heartbreaking because I’ve never loved someone so much. How could you be with someone for that long and not love them? Is this a big deal? Or am I turning streams into oceans?

* we’re in a relationship

*we’ve broken up before and gotten back together

*we’re both in our 20’s