"First off - I'm glad we're getting this sorted out. You know I'll be here to support you as you pursue whatever legal action you can against this scumbag. As you've clued me in on what's been happening I really wish you had spoken to someone sooner, when you started to feel uncomfortable. Letting someone push you into this kind of situation is going to be something that you're going to have to deal with for years to come.
I hope in the end you've learned that anyone who feels like they can guilt or shame you into sharing personal information, photos or video is definitely not worth your time. You are a really kind person but when you feel like you're getting taken advantage of you have to speak up, no one can help if you let things progress this far. I hope you know you're loved and supported and worth so much more than the way that person treated you."
Or something like that.
There is nothing wrong with making sure someone knows that they did something wrong (or even just didn't do something they should have done) while reaffirming love and support.
Often times the only good thing to come out of these bad situations us that the victim learns from them about how to prevent themselves from being taken advantage of in the future. Checking in on that isn't bad, it's responsible and caring.