Engagement

sunny
my SO of 2 years is going into the navy and im heading off to a university within the next 2 years (ive been going to a community college the last year and a half). I've talked about marriage and made him sit through "say yes to the dress" countless numbers of times just because I love the idea of having a big wedding, I always have. I recently discovered that he had $500+ saved up for an engagement ring, i got scared for that type of commitment and shut it down. It was extremely sweet and I was very flattered, but im only 20. I was just wondering if any of you think I was over reacting, or leading him on in a way? any advise please, I think he took it personally. :/