Why is it so difficult?

[Thinlómien]

I never found the Silmarillion difficult, probably because I love history and old legends which it resembles, and also because it was read aloud to me already when I was less than 10 years old, so I learned all the names and places as effortlessly as kids learn new things.

I still have a piece of advice to offer and it goes along the same lines as what other people have said. It's easiest to start with the whole stories: Beren and Lúthien, Túrin Turambar (although I recommend reading Children of Húrin instead, it's much more comprehensive) and the Gondolin chapters (16 and 23). Of course they're all entwined with the general history so you may get confused if you haven't read the rest, but then you should ignore the general pattern and concentrate on the main characters, the actual story. Probably you will grow interested in the rest while you're reading the stories, so then it may feel more rewarding to read the whole book.