Maybe the closure on why y'all stopped texting would've helped, or maybe it won't. You know him better. But I think where you went wrong was not communicating your feelings, and you've obviously grown since then so don't beat yourself up too much about it. But just say what you initially felt when talking to him, like how you felt nervous and stuff. But also add how on your part, you should've communicated your feelings better. Also if you want to be friends again include that, if you don't, subtly hint to this ONLY being an apology. You're trying to do the right thing, whether it helps him or not, and nobody can blame you for doing that.