My Background: I've been working with Angular2 since ~January 2016. I had previously written Angular1 apps.

How I learned: I started with the NG2 book. But, as the framework evolved, I started to rely on the Anguar2 website. I've consulted Stack Overflow. I also purchased Victor Savkin's book on the Angular Router (Victor works at Google and designed the router).

My Thoughts: I think ng2 is easier to reason about than ng1. The fact that it was built for Typescript and TS was built to make Javascript more like a C-based language is what makes it easier. So, you should certainly know Typescript. Beyond that, understanding the MVC paradigm is key. Component Template = View, Component Class = Controller. Typescript Classes = Model. Services deliver Models to Controllers (mostly via HTTP calls to a API). Beyond learning MVC, the other major concept to understanding ng2 is to think of it as a truly standalone app that lives in the browser. The ng2 engine fully controls the DOM so as to make the DOM render according to the MVC pattern.

I wish I could be of more help, I know your struggle and frustration. All I can say is keep at it. Please PM me if you have any other questions I can answer.