Thanks for reaching out to the Apple Support Communities! It sounds like you are having issues with WhatsApp and Facebook Messenger and callers not hearing you. You have tried an excellent step testing in FaceTime and I am more than happy to assist! Check out this article with steps to follow If an app you installed unexpectedly quits, stops responding, or won’t open . This article will give you the best steps to troubleshoot issues with third party applications, along with what to do if you continue to have issues with the apps.
Cheers!