So when it comes to the book I'm writing I'm having an inner battle with myself that I want to add a sci fi part to the horror aspect of the book. My story is about a woman who goes into a parallel world to find an object. She goes through trials of dealing with mad people and even losing her own insanity. That is more of the horror part and that it also deals with lovecraftian beings in an 1890s Gothic setting. Now because this story has to do with parallel worlds than you can guess that it would also deal with more fantastical worlds. like one of the worlds visited is a universe where humans colonized the planets in the year 3000. This makes it into more of an action scifi than horror. What do you think I should do to maybe make the story primarily horror? maybe change the parallel world to a more gothic setting? But I feel like my readers would expect for me to take them to awesome worlds.
I wouldn't worry too much about genre and genre fusion. If horror is your primary goal, you can easily inject some of that into your Otherworlds. Going from the 1890s to a future world, but keeping the Lovecraftian overtones of cosmic dread sounds like it could be really cool. You can always make the future setting Gothic as well (something like Warhammer 40k, for instance) if you want to maintain overall consistency. If you're writing a character which would have no frame of reference for the futuristic stuff, you can have all kinds of fun with description. You can take it to a pretty surreal place, should you desire.
