I agree with Moon8mood and Ragepanda.
I think the best thing for now is to learn to distance yourself from the situation and from your mom first. Even if it is just emotionally. It might just be your writing style, but you seem jumbled, chaotic and angry.
That means your ritual and your magick will probably be chaotic and jumbled as well.
Emotions in ritual are a powerful tool, but only if you have a handle on them. So try to cool down so you’ll be able to think and work more clearly and focused.
It is not a good idea to just wildly throw baneful spells to targets in your home, workplace or classroom. The results might have a very unpleasant backlash if you don’t think them through properly
I’m going on a limb here and guess that you are not very experienced in spirit connection and magick.
So I strongly suggest you hold off on the animal sacrifice and death spells, that is highly advanced complex stuff. Especially animal sacrifice has a huge chance to just be senseless animal cruelty (and illegal in a lot of places) and not earn you any goodwill from the spirit if you are not completely sure of what you’re doing.
Instead of one massive complex thing. Perhaps try a bunch of smaller stuff, you can use tools like divination to help determining what tactics to use. My personal approach would probably start off with a break up ritual for your mom and her BF first.
This is a pretty good one:
After that you could perhaps perform other smaller spells/ rites whenever you can to make their life harder or to cause your targets to fight among themselves. Maybe even combined with a more tactical and less baneful approach of having truths come to light. (The Great Orobas might be of help with that)