Have you ever been disconnected from your "normal" life for an extended time?

This summer, I’ll hopefully be spending three months in Uganda.
While there, I’ll have no internet, phone, television or even newspapers/mail access.
So I’ll be shut off from everything that I know, with no contact to anyone outside of our camp in the village.

The more I start to think about that scenario, the more I start to get really anxious and double think this trip.
Being cut off from internet and the phone is okay… but the thought of not knowing what’s going on with anything besides the 15 or so people that are in the village.. is a scary thought. I can’t even send letters home to let anyone know I am okay.

Essentially, I’ll be dropping off the face of the Earth for three months.
I’m also worried something is going to happen with my sister while I am gone, and I’ll have no way of knowing until I return home.

Have you ever had to deal with anything like this?
How did you cope? Did you cope?
Do you have any suggestions to help me get over this anxiety?