What's wrong with me? Im madly in love after two years of hard work and now I suddenly don't want to commit.?

I love this man with everything I have and I know that he loves me just as much. We've had so many ups and downs over the last two years and I've been there wholeheartedly without flinching even when he wasn't and vice versa. Truth be told, he's made a whole lot more unforgivable mistakes than I have and I've tried to forgive him and work through them each time. This week (when things are on the cusp of perfection and our plans have never been more clear) I realized that I hadn't really forgiven him for any of those things. They really eat me up inside. I've been holding on to them and they still hurt like it was just yesterday. So I ended things with him. I told him I needed time to find myself in order to achieve forgiveness. Now I feel I may have made an awful decision. I don't wanna keep jerking his heart back and forth (or mine for that matter). Is that a good reason to end something so beautiful? What do I do?