Audio/Microphone Issues --- urgent please help

I bought an XPS 4 months ago and have had some audio and microphone issues ever since. I was emailing with support and haven't heard back in over 2 days now and I really need some help getting this resolved. 

First of all, the audio does not get loud enough. Period. Whether it be through the internal speakers or earbuds I pair it with, it is too quiet. 

Second, my microphone doesn't work. I noticed it first in Zoom but it doesn't seem to work with any other application either. It doesn't pick up when I first start talking for a few seconds. So no one notices when I'm speaking and its just embarrassing so at this point I don't even take calls on this device that I spent $1300 on 4 months ago. 

Finally, when I connect to a known working pair of earbuds with a microphone the audio is very quiet and the volume buttons on the keyboard don't work to adjust (i cannot turn it up or down) I have to go into settings and adjust the volume for each individual app. When paired with the computer, I have the same microphone issues on an external device as i do with the built in microphone.

Here's what I've tried so far per Dell instruction:

1. Start  > Settings  > Privacy  > Microphone > adjust with each app

--- zoom is not an app that has adjustable settings listed here

2. uninstall realtrek

--- this disabled the mic and speakers and i got a "no speak or microphone connected" error.

I am a full time grad student and everything i do is remote. I really need some help with this asap. 

Thank you for your time!