We are glad you emailed us about this, it sounds very confusing. And yes, please feel free to write us back. Just hit the reply button and we will receive and respond to your reply. Good question!
Sometimes people who are shy just have a tough time letting people in. And it really isn't a bad thing at all. It is very natural and healthy for people to have up boundaries and not let everybody in all the time. It is how we protect ourselves. But when our boundaries are too big, we may shut too many people out and isolate ourselves.
At your age, it is very natural that romantic relationships don't last very long. There are so many pressures and life changing things going on that middle schoolers often will push people away. And romantic relationships are hard to figure out. Sometimes when we aren't sure of how to do something or what the rules are with something, like a boyfriend/girlfriend relationship, it may just be easier for us to not get engaged in them. And that is okay!
Always remember, if things are meant to be between you and this young man, than it will be. You won't have to force anything or do anything to make it happen. Even this break up won't end up mattering. But don't feel like you have to force anything or do anything extra. Maybe just tell him you are sorry for the way the relationship ended and leave it at that. Take your time. You got a lot of time and changes ahead of you. A boyfriend certainly isn't a must at this point.
Whatever the reason you aren't letting him in, try not to beat yourself up to much over it. Something wasn't working, it wasn't meshing for some reason and it probably isn't because you or him did anything wrong. It just wasn't the right time. Slowly time will heal the hurt you and he are feeling from the breakup. Try to befriend him again if you wish and take things slow.