My iPhone all of a sudden says E instead of 3G?

I have an iPhone 4 and I've had it for about 5 months now and it has worked decently fine. I've never severely dropped it or had water damage to it but it all of a sudden isn't working properly.

It displays E instead of 3G, I'm not getting/sending text messages, and none of my apps work properly. Safari continuously keeps crashing. What's wrong with my phone?

It put you on Edge (2g) just means no 3g towers available around you… Really slow service but nothing bad, no worry.

3G not available in your area.