Letting anyone else know that you are going to CTB is one of the worst things you can do if you are genuinely wishing to pass on. Majority of people, especially those you love/love you, are going to immediately take drastic actions to make sure you're "safe."
A lot of those folk get seriously upset and emotional, force their way in on your choice and tend to make it about them and how much you upset them. However, most of this behavior is genuinely coming from a place of love and concern.
Personally, I hate people knowing that I'm suicidal, or have been in the past. It makes everyone go on high-alert and treat me with kiddie gloves. The amount of babying and forceful "help" makes me feel suffocated, and like they don't really care about what I'm going through. They'd rather have me "work through it" and continue to suffer, pushing me to live for nothing. Mostly for their own benefit mind you.