Are we more than friends?

I met this girl at a summer job last year and we clicked. We started going out with mutual friends and got close.One day she told me "I think I've a crush on you. Is it weird?" She had a boyfriend at the time (we're both girls) so I laughed it off. Another time she said "I'm falling for you."She used to invite me over to her house while her parents slept. We would smoke and cuddle in her bed, then she'd sneak me out by morning. One day before I was about to leave, she kissed my forehead and said she loves me. Then she leaned in and kissed the tip of my nose and giggled. I found it a bit off because we usually have intense eye contact and I've caught her several times staring at my lips.
Then one day her mom walked in on her leaning on me on her bed. Her mother called her disgusting and slapped her infront of me. (No not exaggerating)

She travelled back for college and would call me everyday and we speak for hours at night. She always tells me she misses me and my cuddles, and how much she adores and loves me. Sometimes she sends me "sexy" photos/videos revealing her body. And once when we video called she was only wearing a bra and sweats.
Then we argued because her boyfriend (who she has a rocky relationship with) thinks I'm a bad influence on her, to which I said that I'll be away from her. She kept calling and left me a message* "If you leave me my life will be screwed up. You're so special to me, you're my entire world. We cannot be apart I can't live without you"

She told me she feels her bf is cheating on her and she doesn't feel the same way she used to. And then she broke up with him.
A few days later she told me she had a dream where we were fighting and then I kissed her lips. She said it felt good. I avoided that subject but she brings it up sometimes to joke about it.
She said she wants to travel with me abroad to a new college and move in together. And so we did.
Initially I supported her financially (her ticket, our dorm, pocket money)because her parents weren't helping and I shared mostly everything with her.

We would fight from the beginning. I had an alcohol addiction, and I was recovering from some childhood trauma. Sometimes she’d slap me or bite me really hard which drew flashbacks on me. She would claim that I tried to kiss her when I was drunk (though I didn't remember) and asked me if I had feelings for her to which I replied No. So we decided she should move out. Anyway it got worse. She had told to kill my self (knowing I was suicidal), I grabbed her by the neck and we fought physically and cops got involved.

We sat down to speak once after the police incident. She said "we tried and it won't work out. I don't want you. I feel nothing for you anymore." When I asked her what I've done to deserve this, she replied "I cared about you. And I was in love with you" after a pause she continued fast "as a friend."

For the next 2 months it was a push and pull game. I'd chase her and try to fix it, she'd push me away and say she needs space if we were to fix it. But as soon as she sees me moving on, she stops me. For example; when I accepted it was over I gave her a teddy to say goodbye. She ended up going out with me and another friend that night. She got sick at the end, and i ended up cuddling her and sleeping next to her in her new room. We had another major fight after that and I found out that She's also been going around and talking badly behind my back to boys especially, saying I was gay or obsessed with her, and also spilling my secrets. I also found out that before she got close to me, she went and told people that I liked her.
After all the problems she caused me, I left uni for the semester. She told me she was going back to her ex to get engaged but again I found out that was a lie, and she's desperate to have him back so he "could take her out"

From my side I did love her and care for her as a friend and I miss how close we used to be. We knew everything about each other and I kept her secrets and just wanted to help her. No bad intentions.

I want to move on and I'd like to get some clarity from her POV.
Was she using me? Was she afraid that I liked her romantically? Is she mentally ill? What could be the possible reason

People do this all the time....you get involved with someone who is unsatisfied in their relationship, they will fill the gap emotionally and sometimes physically with someone other than their SO. It's called cheating. Yes it's selfish but they are so blinded, they think it's big, it's intense, it's real....but it's just an escape. It the moment it felt right, but when it dies down, and reality sets in, like a huge hangover, they regret ever getting involved. You should never let yourself be so vulnerable to someone who is taken...this is your punishment..heartbreak and confusion. This friendship stuff, is bull crap....your intentions are very clear, even tho you won't admit it...this was all about you getting the girl. Don't do it again.