I want to get married. I'm ready for it and I felt our relationship was too (we were living together). If he doesn't want to get married I can't change that and I shouldn't want to and vise-versa. Trust that good things fall apart
Ultimately, of course, you want what you want so I can't disagree or argue! But, your comment motivated me to articulate my thoughts on this.
"Marriage", I think, is 3 separate things:
Suppose for the sake of argument, OP has a very healthy helping of #1. This guy is everything OP could want - loves her, cares for her, has been there to support her in the worst of times. Maybe he even cleans the house every day and wakes her up in the morning with a poem and breakfast in bed.
But let's say for whatever reason, he's against "marriage". Maybe like another commenter said, it's because his parents had a rough marriage and he is afraid to repeat it, or maybe he's staunchly against marriage as a political institution, feeling that it's a private matter to be defined solely by the partners.
Suppose further that he's down for a party with cake and suits and a dress and all that! He and OP have all the most important stuff already! They only thing they do not have is a legal contract.
In this case, one has to think very carefully about that desire for marriage and what it really means. A husband and a fun wedding are great fantasies. But sometimes the forest is lost for the trees, and we forget that it's the loving relationship that lasts longer than the party and means so much more than the legal contract!
If someone is willing to end a beautiful and loving relationship because they must have that marriage contract, it must be a special kind of dogma where they want that piece of paper that binds partners legally more than they want the love that binds their hearts.