I definitely have huge phone anxiety, and have always been nervous about calling my representatives, but I finally did it. In support of the ceasefire in particular.
5calls.org makes it really easy, which I really appreciate.
If you're in the US and you've always hesitated, I do recommend calling and making your voice heard. It's not as scary as it seems. The lady working the desk for my representative was extremely friendly and the call took like 30 seconds. Plus, it feels good knowing this one action has like 5x influence multiplier over tweeting a hashtag (although you can always do both!)