I think she may be jealous of you for some reason. Think if you may have hurt her or done something without realizing. But i think its jealousy as she is taking the piss out of you and hurting. I think you and anna or just you should speak to her, it maybe theirs something at home bothering her, which to the point she takes it out on you. Ik im giving alot of examples, but hope this helps.
It could just be the girl is crazy i mean she made u bleed???
First of all, your rant isn't pathetic. What your friend is doing is abusive. A friend understands when you're uncomfortable with something and stops. A friend doesn't take pictures of you and laughs at how stupid you look. A friend doesn't laugh at you and insults you.
You need to take a deep breath, take a step back and examine 'Do you want this type of person in your life?'
You're free to live how you want but you need to do what's best for you. My advice is to cut Elle out of your life. It's clear she doesn't listen to you when you say 'stop' and how her treatment affects you. Surround yourself with people you know will support (close friends, family), tell them what's going on for moral support, and just stop talking and seeing this Elle.
I honestly hope this gets better for you. You deserve better than this. You deserve to be treated with respect and common decency.

*inhales* ok, so,
my friend ( let's call her Elle) has been acting strange. it started about 2 weeks ago. elle has been one of my best friends. recently she's been hurting me and i don't know how to deal with it.
it first started with hurting. it used to be just teasing like nudging each other, but now she's been pinching me really hard when she got annoyed with me, to the point where it started bleeding. i told her to stop doing that so she did.
then she started making random remarks about me. calling me pimple face, telling me my hair looked horrible, yeah y'know that stuff. i'm a pretty chill person so i just ignored it at first. but then it got worse. the pinching started again.
i told elle to stop again but she told me to stop acting all innocent and cute in front of her. she's been also excluding me out of a lot of things and when i try to press and join in, she just glares at me or makes another remark. most of these things i've just brushed off because i'm pretty chill, but it's slowly building up.
then she started taking photos of me and laughing at how stupid i look. i told her to stop but she just thought it was funny. one of my other friends (let's call her anna) anna saw elle taking photos and privately asked if i was ok with it. i was not. i told her i was fine.
ahhhh i'm so frustrated! i dont know if i hate her or not. ty for listening to my pathetic rant ヾ(❀╹◡╹)ノ~