I know: politics.
I grew up with a phone phobia. Anytime I had to make a phone call, my heartbeat would speed up, I'd start sweating, I'd procrastinate like my life depended on it. Sometimes, there were tears. If I could, I'd write a letter instead, or find someone else willing to make that call. I still write down brief outlines of what I want to say when trying to save a voicemail message. Even now, outside the context of work, you have to be a wonderful combination of someone I like very much and whom I feel extremely comfortable around in order for me to call you. It's nothing against the people I don't call, and for some people, it just takes me longer to get to that point.
I like people a lot in general. There are very few people I meet that don't inspire an immediate fondness in me. That said--I don't like crowds. They're noisy, unpredictable, and while I love hugs, I don't like being shoulder-to-shoulder with people I don't know.
Yet, here I am: marching in the Women's March and calling my senators. I ducked out of the Women's March at lunch, and yes, my palms still get sweaty and my neck burns when I make that phone call (What do I say? What do I SAY?).
I understand that it's even harder for some people than it is for me. I just want you fellow introverts to know that you're not alone. If you want to call, if you want to march, if you want to write letters but you're having trouble--you can talk to me (or drop me a line) and I will listen.
This is all overwhelming, I know. There's so much going on and it's difficult to know what to do and when. I just can't bear the thought that I will one day look back and wish I'd done more.
Things that helped (or are helping) me:
March with friends
Being with friends can help insulate you from the crowd, so at least the people who are shoulder-to-shoulder with you are people you know.
Write down what you want to say
Write down what you want to say before you make the phone call. It helps you to not clam up unintentionally or to stumble over your words.
This can help anyone who wants to do more. I've found it a fantastic organizational tool for projects. Keep your tasks organized on a virtual corkboard with a calendar, notes, and due dates. Checking things off as "done" is immensely satisfying and it helps me to know what I want to accomplish day-by-day.
Don't know what to write or what to say? Google some templates. If you want to personalize, you can do so from the template.
Good luck out there.