It seems to me that the two of you have different ideas about what it means to be dating. He doesn’t see a problem. You do. And that is the real problem. There’s no “right” way to do a relationship except what is right for the two people involved. You two can’t even seem to find a time and a place to talk about it, much less reach an agreement.
I’m sure your boyfriend must be sweet for you to be willing to put up with such a big difference between you for so long. But it just may be that his style isn’t for you, however sweet he is. At 15, you are not committed to staying in a relationship that isn’t what you want or need. My best suggestion to you is that you take a time out and see who else is out there. There’s probably a guy just hoping to find someone like you.
And — stop apologizing for your grammar and do something about it. This is your time to learn and practice and get better at presenting yourself in writing. Most good jobs require good written communication. Please, please take care of yourself. Don’t cheat yourself out of a good future by not taking your writing classes seriously.
I wish you well.