How should I dump my gf?

This girl asked me out and I said yes only because I thought it took alot of guts to ask me out and I was under the influence. Anyways she is obsessed with her horse and I usually love all anmials but I am starting to hate that horse. It is so dumb and almost bit me. Anyways, she isnt good looking, my friends said 4.5/10 is being nice, and I agree. She has really bad acne and gross teeth. Anyways little things she says are starting to piss me off, she thinks her dogs can see in color, which I told her is wrong and she was like "how do you know have you been a dog" Anyways she always wants me to make a move on her and she wants to hang out everyday, meet inbetween every cl and always makes me do stuff with her stupid horse. She calls him her boyfriend and when her last bf broke up with her she was like "how come the only good boys walk on 4 legs and 1500lbs" anyways I want to ask this blonde bombshell out but I want to dump my loser gf. How can I do it so she thinks its my fault?