I do agree with what MsLady has said.
It happened to me something very similar with one of my best friends’ bother.
I was also very young but I tried my best to go on with the relationship. I thought I was very lucky and that I couldn’t ask more.
The thing is that I was very coward. I asked him to give me a time alone but in my head, I was breaking up. The thing is that I had the poor guy coming to look for me everyday to my secondary education building so up he finally told me that he meet a girl he wanted to try it with and I felt relief.
It was also very good for him because he met who is now his current wife.

Hope my experience can help you. You are very young and you have the right to have experiences and break hearts. And it’s the best for both parties, believe me.