I don't mean to ask the obvious but....have you checked your microphone settings on your Mac? Maybe it is set very low. Alternatively - are there other softwares that you can record you speaking into the same microphone and then seeing the sound level that it plays back at? This way you can see if it is consistent across different programs. If it is, then it would point to either your microphone settings or your microphone. If you do use things like Zoom with your microphone you do need to be aware that some things will have custom settings within them that override what the computer is set at, but those settings only apply to that program. What I mean here is that if you have no issue in another program, that might have the microphone input jacked up from what your computer is set at. I am putting in a "source" so there should be a link to Apple's web page that tells you how to change the microphone setting so you can test if that is the issue.