Dear Lydia, according to my experience, the fact that students sit the exam remotly is already a good way to reduce their stress. In addition, you could tell them that they can have all the teaching materials available (i.e. open on their desk / computer), if they need to have a glance at something.

I agree with Patrizia. Speaking assignments should be grounded in encouragement rather than testing. Allow any support the student want to use, in preparation and in performance. When they no longer need the support they will just not use it. Meantime, they are encouraged by knowing that they are allowed to use the support. It's not cheating – it's learning and growing.

While many students are confident and might love to talk in front of the class, but others might be too shy or embarrassed to speak out loud. Using roleplay can help to increase learners’ motivation and to give them a big opportunity to practice their speaking. Asking them to video-taped their speaking tasks and uploading to the social media can also be another way to arouse their interest and enhance their motivation.