Ex refuses to be friends again

I just broke up with this boy I was dating for a short amount of time. I'm 15 and in my opinion it was a minor relationship. I broke up with him simply because I felt uncomfortable and I preferred us as friends. Even though everything made theoretical sense to me, when I said yes, it became clear later on that it simply wasn't for me, and so I felt comfortable breaking up with him. A week later, after him being really upset as I did expect, he texts me saying that we can't ever be friends again because it will be too awkward and he'll never be as happy with me as he was when we were dating. I find this really difficult to take in, because I feel like I've completely lost a friend, and thrown away something I used to have.
Is there a way we can be friends again or will it always be awkward as he says it will? And is he making a valid point?