When it says exit steam, maybe try making sure you FULLY exit steam. If you are on Windows, open your tray icon and right click on steam and press exit. Or you can just kill the background process through task manager. See if that helps you or not. I have also heard from a few places that Windows 7 does not work well with HL2 although I cannot confirm this myself.
Hope you can find a fix, A lot of other games besides Titanfall 2 are not hooking either.
Another update, not even sure what I am doing or if I am doing anything but some more games like L4D2 are just suddenly working, Titanfall 2 still has the issue though.
quick update, I uninstalled openxr and I got Farcry 4 to run once, and then about a minute in it crashed and I am back to square one of no game working again.