I first read the Hobbit and LoTR when the LoTR movies came out back in the day. I enjoyed it quite a bit but it was tough. I decided to reread them a couple years ago and got completely hooked. What helped, though, was often pausing my reads to watch some youtube videos about some part of the book I was in. Most youtube videos on Middle Earth are pulling from the Silmarillion and his other works. This gave everything a much greater depth, knowing a rough history of each part of the book. It no longer seemed like some adventure story, it seemed like an active tale taking place in a world extremely steeped in history. With timelines of hundreds of thousands of years you get a real sense of scale of LoTR. I've since read the Silmarillion.

My favorite aspect of it all was if you look at LoTR as "modern day" when most regular people no longer believe in magic or even know if the old tales they grew up with are actually true. These Hobbits are quite like that, but are then thrust into this story where this one ring that was lost like 3000 years ago is actually real and the being that created it is alive and wants it back. The LoTR is sort of the final epic tale of Middle Earth. The characters often allude to the other epic tales like Beren and Luthien, Fingolfin vs Morgoth, etc, but don't realize they are in one of these tales until about halfway through the journey.

You should definitely go back and read the series once you've finished the Silmarillion.