Im about to lose it

To make this as short as possible my mother hates animals for no reason, she always has and always will. Well today someone was giving free baby kittens as their mother just died, I really really wanted one but since my mother just can't stand animals and because she can't bare with it for her own child I wasn't able to get one:( im not even a kid (older teen), so its not like I can't take care of it. Shes just doing this to spite me. Everything in my life has been adding up for a long time, im really about to snap, im scared im going to hurt her or someone else.