I used to work as a business intelligence (data analyst). It requires speaking sometimes but the core of the job lies elsewhere, i.e., knowing how to work with data and how to analyze them. Now I work as investment banking analyst. Most of the time you work alone on an excel model or slide deck. Nevertheless, it requires more speaking and sometimes with clients which can sometimes get messy. However, people are used to seeing freaks in top finance so they usually assume that you are very smart. So if you want to make good money and don't want to do CS you can do Economics/Finance. There are plenty of jobs that pay well and speech is not the most important trait.