I agree, this is extremely disappointing. Adobe is giving us a completely untested software release and now does not even want to address all the problems. Ridiculous.
How do I uninstall this AWFUL Update and get back to work?
It sounds like you are having a frustrating time!
I'm really enjoying this new version of AE and find it to have fewer issues overall, but I know some folks aren't having as good of an experience as I have, so I've been trying to help in the forums where I can. If you would like your specific problems solved, make a thread with as much detail as possible and I can try to help and/or point me to threads without responses. (I've been away from the forums for a few days due to personal life interfering with my forum time and it's been a holiday weekend in the USA, so many people have been away...)
Anyway, to get you working in the old version again...
CC 2015.3 is a full version install (pretend it's CC 2016), so it installs alongside other versions and is not just an update to CC 2015. The problem is, the CC app defaults to removing old versions when you install a new one so it can seem like a simple update. (This is a very bad idea on Adobe's part, but that's another discussion.)
The good news is that you can install all of the old versions you might ever want. Your AE CC subscription includes CS6, CC, CC 2014, and CC 2015 in addition to CC 2015.3. This page shows how to install the old versions.
So this will enable me to install cc 2014? That way Adobe can fraudulently charge me $600/year at $50 a month for a version that is useless to me. Wow, I love Adobe. Adobe has succeeded on the backs of customers like me that have used their products for over 20 years just so they can flex their corporate muscle alienate their customer base because they have a monopoly defraud us out of our money at will.
It will enable you to install any version you want from CS6 onward.
It is all included in our subscription.
We are not being charged "fraudulently" for the new version; we are being charged for our subscription to the entire collection of software including the entire host of versions. We are being charged for access to all of the software. Some versions will work better than others. Use what works best for you.
For me, on my machines, CC 2015.3 works great. I haven't used an older version at my freelance studio since it's been installed. But I'm not going to complain that I'm being "fraudulently charged" for CS6 that doesn't work well on my El Capitan machine...
I understand being frustrated that the latest/greatest isn't so great on your system - I would be frustrated too - but to complain about fraud seems to be taking it a bit too far. Plus, ranting can get in the way of us being able to actually help you get the newer version working on your system (which is what I would prefer to do because I want you to enjoy it like I am). Those of us here in the forums are just fellow users like you who are volunteering our time to help others. Let us help you!