Phone Microphone only works in calls but nothing else

Recently, my phone's microphone stopped working which means it doesn't record sound in videos or audio recordings and also doesn't work in apps. The only exception is phone calls where it does work. Why is this? This has happened a long time ago before and it fixed itself so I left this issue for a while but it's been about a month or so and still nothing has fixed! I need my microphone to work asap because I need to record videos WITH audio for my school project! Need help!

Note: I have tried rebooting my phone