To give you a different perspective.
I married dh because he wanted to get married. He asked several times and I suppose we were quite young and I wasn't assertive enough in my opinion. And it seemed very important to him. We have two children, we have been together 15 years. I probably shouldn't have got married. I love him. I love him completely. I never want to be with another person. I fully plan to grow old and grey with him. We have two children. We're extremely happy.
Had I had the courage of my convictions, I would have gently turned down his proposals. We'd still be together (I hope) and have our wonderful children. But if I'd managed to be firm back then and he'd asked now after 15 years and 2 children, as an older, wiser and more together adult, I'd have had no problems with saying no.
To me, there's no such thing as 'loving somebody enough to marry them'. You love somebody or you don't. You want to get married or you don't. You don't use one to measure the other.
One of the happiest relationships I know has lasted 35 years and 4 children. They got married last year and told nobody until they let it slip recently. They did it for practical reasons actually but it tells you nothing about their lives together.
I know you seem hurt but it's ludicrous that you can go from happy and secure with somebody to planning to leave because he has a different opinion to you. Talk to him today. Don't 'let him stew'. You aren't children, this isn't something he has to feel bad about. If he doesn't want to get married, find out why. Not being married to him has been enough so far. Why is it a dealbreaker now?