Outdated Photoshop Question

Hey everyone, 

So I've been using a 2017 version of Photoshop for years and have had almost no issues. I use an older Mac (2011) and I don't do anything that intense on Photoshop so I never found a need to upgrade. I do use the creative cloud suite because I make videos so having access to all of those apps is very useful.

When opening up Photoshop today it would not let me sign in for whatever reason. When calling customer support they said it's because this version is no longer supported. I used this version a week or so ago so I don't really see the problem? I'm using the trial version just to get my current project done but they said once the trial runs out I won't be able to sign in anymore. 

My Mac is on macOS Sierra Version 10.12.6 and I don't believe I can update much more than that on my current Mac.

I pay for the Creative Cloud every year and I'm disappointed that my perfectly functioning Mac may not be usable at all soon. Does anybody have any suggestions? (Besides buying a new Mac I cannot afford that right now)