I too have been working with CBT and sometimes it is very hard to identify the type of distortion. I have a hard time even remembering what they all are called. I have an app on my phone that helps out tremendously with this. It's called Depression CBT or if you can't find that one pretty much any of the CBT apps do the same thing. You put in the thought you are having and then it gives you options for the type of thought it is and then suggestions on a way to reframe that thought. It also has the definitions of all the different types of distortions you can have. Not only does it help you learn it, it also serves as a record so you can see your progress. Hope this helps, CBT takes alot of mental energy but it seems to be working.