Giving up on Dracula - for the 2nd time

I know that when I "read" Bram Stoker's Dracula many years ago when I was I'm guessing about 14 I really loved the book for a while but I think I got bogged down in the many diaries and the scenes in England and never finished reading the novel and, guess what, same thing now: after getting off to a great start the novel just bogs down and slows almost to a halt. It's as if Stoker were paid by the word or by the page - he just drags the story along relentlessly, ploddingly, and we the readers are way ahead of him. Here's the main problem: why are the first 4 chapters so engaging, and the rest of the novel so dispiriting? Because in the first 4 chapters we are closely watching a man in jeopardy: Harker, the diarist, ventures into Dracula's castle with no idea what horrors await him, and over those four tightly written chapters he gradually understands that he's a captive and in mortal danger. In other words, we completely engage with him and his plight. But the many chapters that follow, in London and environs, involve no such jeopardy: we are with characters who are trying to make sense of the strange behavior of the people (and animals) around them - stuff we can easily figure out, though they cannot - and they are by and large never in any particular danger. The tension's gone, the story's deflated, and I - twice now - have lost interest. Too bad - it would have been a great 200-page novel, perhaps - but it has no doubt been influential and, though Stoker did not invent the vampire myth, it has been the source and model for numerous films, books, and parodies that have followed in its tracks.