Without exact info about your project nobody can tell you much, including specific info about your audio sources, audio settings and all that good stuff plus system information, possibly screenshots, exact output settings. You've written a lot, but realyl not said anything useful to diagnose the issue (other than saying that these are sucky bugs in AE).
You're new, so you wouldn't have known this -- you never, EVER upgrade software in the middle of a project. There are just too many things that can go wrong, as you are now painfully aware.
Your best bet is to revert to the older version.
The other thing you can try is go back through the auto saves and find the newest version that still has audio.
If I'm doing something complex I save with a different name at key steps, that allows you to go back if you discover a hidden problem later, and always use the feature that incorporates the time into the name of any render and export you do. The auto save files are not big, it's not a huge deal to do.
I use a very methodical file naming and storing system. That's the roof of the Ae/Pr house, you must be consistent.
If you are not familiar with auto saves just search on the term.
Good luck. Painful lessons teach the most.
I went through one of my auto saves but they automatically convert to the new version if I try and open them, which I would assume would apply the same problem
I add whatever info you need. But there is one thing that may be it. It seems the easy enable audio icon thing on the far left of each layer seems to be grayed out. I can see the icon, it just seems darker than icons around it. maybe it is disabled and I don't know it?
Well okay guys. I fixed the issue. I do not know why this is but I just clicked the isolate box for each layer and it enabled the audio
Open the oldest one and see if it works. If it does not then that path is closed.
You can reinstall older versions of Ae, a few upgrades ago people screamed about this sort of thing and they enabled that. The older version may still be there, if you are on Windows from the control panel open "all programs".
If it is not there search this forum and you will see lots of posts that explain how to install older versions.
One nice thing about Adobe products is because of their complexity they have, over time, added many ways to go backwards.
Good to hear! Save frequently, I use different names at major inflection points, and keep a record of the changes. I find if something strange happens I can go backwards until I find the problem.
It is a complex program, learning how to troubleshoot is an important skill that is not taught enough.