I think it's a tricky one and possibly different for everybody, but things which might be useful (or not):
1. Keeping that date free from commitments and surrounding yourself with things that comfort you and feel safe and grounded in the present.
2. Make a list of safe people you can contact or safe places you can go and make sure at least one trusted person knows that it's a significant date and that you might need additional support.
3. Alternatively, plan something really fun to do, maybe something energetic or a favourite thing to do with a favourite trusted person. Sometimes having too much time to think brings things to the fore more.
4. Make an arrangement with the mental health team so that they know you might need some contact on the date.
I think that's all I've got, but I think one of the most important things is reminding yourself that it's 2019, that you're safe now and that the terrible thing happened but you've survived for ten years and you can keep surviving and will be okay.
I think it's really smart to be aware of this and give it some thought like you are. Your knowledge is power, to add a bit of a cliché (sorry).