I'm so sorry you are dealing with this. It's a pretty tight spot to be in.
First, Welcome to PC!
Second,
Do you know anything about where he lives? Knowing his skype info may help in locating him. You can call a crisis line and speak with them on what the best course of action could be.

either
TeenHelp Adolescent Resources: 1-800-840-5704
or
Depression Bipolar Support Alliance: 1-800-826-3632
or
Lifeline
(which has a number on there as well)