In the long run, I believe you will be happy to have upgraded to iOS 8. It will take a while for developers to take advantage of the new features, but it will be worth the current inconveniences. If you made any mistake it was in upgrading a bit early, but in this case it would only have been putting off the inevitable.
Once QuickOffice was purchased by Google, it had a limited life. I'm surprised it lasted this long, and who knows, maybe they will update it for iOS 8. Google is unpredictable.
I don't have any personal experience with an Office 365 subscription, but what I've seen of the Microsoft apps in their free mode is encouraging. The feature set is comparable to the iWorks suite, which is pretty much the gold standard on the iPad. While you'll have to re-learn the interface I'm sure you can accomplish far more with them than you could in QuickOffice.
At the very least, you're not going to fined anything with the same level of compatibility with Office. And $70 a year for the personal subscription isn't all that painful when you consider that you won't have to pay for updates. Keep in mind that Office 365 includes the use the software on a computer and the web apps.
Still, there are other third party Office compatible apps, and perhaps you should give them a try. Most offer a free, limited, version.
Good luck.