Tanya, please do not stick with your fiance because you think you can "change" him.
That is a sure recipe for divorce court.
You have been given very good - and truthful - answers. In your original question, you state that you and your boyfriend have been together for nearly a year. The fact that you now insist that he just needs some time because he had not been in a relationship for quite some time (before he met you) speaks volumes.
It says to me that my guess was absolutely dead on.
Your profile shows that you are 28 years of age. I am presuming this means your boyfriend is about that same age, or perhaps a smidge older. He hadn't dated anyone for five years before he began his relationship with you, he is "all about having fun," you haven't been physically intimate for three months and you've been together not even one full year; is that not correct?
And you believe he seriously asked you to marry him?
Please, honey. Wake up and face reality.
Your boyfriend may love you. Indeed, he may ONE DAY decide he wants to get married. He may even decide he wants to marry you. He's just not ready now!
You pushed him into it, sweetie. That's why he acts the way he does.
I'm sorry, but it's the truth.