I know you love him, but it's important to remember that relationships are built on more than just feelings. Communication, respect, and consent are also extremely important. I know you love and respect him, and I'm sure you get along with him just fine, but he is no longer okay with being in a relationship with you.
It's not that he doesn't love you or respect you. Those are still there. But if he doesn't want the relationship, you have to respect those boundaries. As much as you want this to continue, he's explicitly stated that he no longer consents to having this relationship with you. If you truly love him, you need to respect his wishes and give him space.
It's important that you accept the fact that you are no longer together. It sucks and it hurts, but you can't force him to change his mind, and even if you could, it probably wouldn't feel nearly as good as if he'd decided on his own that you two should still be together. I'm so sorry, but the best thing you can do right now is let him go.
Find a brand new independence. You can be happy without him. That's what the best relationships are like, anyway: rather than depending on each other for happiness, you find your own, independent happiness and then find someone to share it with. You are just as wonderful a person without him, and even if it doesn't feel the same, it's okay.
This isn't much of a change. There's not really much about it that makes you happy. But change is something that's constant (ironically). Everything changes, whether we like it or not. The important thing is that you take this change and use it to find a new happiness. Find a new hobby. Learn a new language. Travel. Have a night out with your friends. Do something to get him off your mind. If you're actively trying your best to not think of him and distract yourself, eventually he won't be on your mind at all.