Circuit analysis and general study tips
I went through exactly the same struggle you did.  My first circuits class was the hardest one I had taken up to that point.  Now I'm a professional Analog IC design engineer so it is possible to learn this stuff.  In my opinion Horowitz and Hill is highly overrated and people who read it think they understand electronics.  I've had much more luck with Sedra and Smith and Introduction to Electronic Circuit Design

To become a good circuit designer (and analyzer) you really need to get a grip on the rules of thumb and how to analyze circuits quickly.  I very rarely write a bunch of node equations and solve them any more.  The Introduction to Electronic Circuit Design is especially good because it teaches you how to recognize common circuit blocks and how to quickly get their gain, input/output impedance etc without doing a bunch of algebra.

If I were you, I would focus on learning the rules of thumb and solving as many circuits are you can, over and over.  Then go back and learn more detailed theory to fill in the holes when you need it.  

Good luck!