hi and welcome to the forums.
there are many conversations in life that can be difficult. And there are some others.
the worst one for myself was talking about suicide with my wife. Although that one I was with wife near the laundry. Mostly we would chat at a coffee shop. Whether you invite them over, or go out somewhere, initiating a chat can be hardest bit. Once started though ... hard to turn back and redo, and there can also be a feeling of the weight being lifted off your shoulders - it sounds like the "not telling" is weighing you down?
And for me, it typically starts with... "there is something i have to tell you..."
True friends are supportive.
Having said all of that, you can easily put that question out to google and see some of the stories on the first page. Finally, if you want to do it, go for it. If you don't want to ... that is also OK. It does not make you fake.