As strange as it sounds, a lot of it is about repetition. It's tough when you start out, because not only is there so much to learn but it's like a different language.
I had a similar feeling this morning - I was looking at placenta slides, and trying to figure things out. And in looking for good reviews of placental histology and pathology, over the past couple of weeks I have found a 100 slide study set with guide, chapters in dozens of surg path and histology books, and 700 page books dedicated solely to placental pathology. And this is just a part of it all. Every branch of path has its own standard textbook. You can read a chapter on the liver in Sternberg, for example, think that it is way too much to ever master, and then realize that there is a 700 page book on JUST the liver.
I don't think it's reasonable to expect to learn a ton right away. A lot of it is learning the basics, and learning HOW to look things up, or where to start when you hit a wall.
Having done a year of AP, for the first 3-4 months it was incredible. Not only did you have to learn about all these diseases, but you had to learn how to describe them in a dictation, how best to demonstrate it on a slide, and how to interpret the slide. But gradually it started to click and you can focus less on the technical and procedural aspects and start to learn more. Go about it systematically, I guess. Try learning about new things every day, but don't try to be an expert in everything right away. If you see something you have never heard about or don't understand, read about it. Then you'll see it again and still be somewhat confused, so you read about it again.
Autopsies are similar - don't know if you have done those yet - but all of a sudden you are flooded with anatomy and dissection and somehow expected to know it. The good thing about path is that there is almost always someone around to help you understand and learn.
Clinical path too - just when you realize that AP has boatloads of stuff to learn, there is also CP where there is almost MORE information.
JoeD is right - it takes a lot of time to become comfortable, and when you do become comfortable, a lot of it is that you still don't know a ton, but at least you know how to find the answers.
Glad to hear you're enjoying it though - me too!