I don't have an outline. Maybe that's the problem. I keep it in my head.
Maybe you should make up names for Chapters and work from there... then tie everything together in the last 3 pages.
I don't formally outline. I have a basic list of things I want to have happen and I end up with arrows and cross outs all over that list. My characters take me on detours, and that makes the stories realistic. Life does not run smoothly. You are a writer - a story teller. Tell the story the way you wish it could be told to you. Write a story you would enjoy reading. Yes, later on you will rewrite and edit, but you will enjoy it more if it is a story line that you find fascinating. It is your book - enjoy.
I'm not big on outlines, either. I'm in the midst of writing a set of books but it's based on medieval fantasy rather than horror. I generally work out what will happen in extremely general terms, say a Visio chart with maybe thirty bubbles for half of the book (or, if I can't figure out that much, at least a third of the book). For me the first third is the hardest, as it's all still amorphous, but then I tend to progress logically, with a vague goal in my head about where and when the book should end. It then becomes an exercise of getting the plotlines to where I want them but still trying to keep it interesting. I'm not a huge fan of outlining everything in advance -- while I know generally where I want things to be, my characters don't. I think it's more natural if I build the little details as I go, especially dialogue. For me the transition chapters are the worst -- getting characters to a destination while keeping it from getting dry. It's times like those that I have to constantly challenge myself to think in terms of character development; it's not what happens that's important so much as how the characters view it and what effect it has on them.
For endings, I tend to start at the most abstract level and move in increasing detail. Happy ending or sad? Bittersweet, perhaps? Are the characters on an emotional or personal journey, and if so, what is the significance of the ending to it (for example, two central themes in my story are redemption and responsibility). I tend to just work the really low-level details out logically as they have to be believable (just how *do* people free a captive without being discovered?) and concentrate on what it all means for them. After all, readers must first and foremost throw their lot in with my characters or it's all moot.