I loved this! Draco's reason for using the blasting curse on Harry just feels right, and seems like something he would do - the anger, the desperation he felt in that moment reminded me of the Draco in the last two books. And then he immediately realizes what he has done, but it's too late to take it back. And then when he understands that he has always just wanted Harry to see him - that is how I see all his actions in the books too.

He takes a few deep, soothing breaths, banishing the anger that’s started to build up in him.
Harry seemed a little too accepting at first, but then I read this line and realized that in his determination to not let anything ruin his life now, he might just be burying the anger as deep as he can. But if he is, then he is just postponing the inevitable explosion. I'm not sure if that was your intention or not, because I didn't see that line mentioned anywhere in the comments, but that's what it hinted at for me.

I would also love to read a sequel, and if you aren't sure when to set it, you could always write more than one! ;)