How can I be nicer towards my friend!?

So I'm pretty close to losing my best friend. I'm always "mean" to her... Okay yes I am probably very mean to her. But it just doesn't seem mean to me because I'm pretty sure I have schizophrenia, or at least a form of it. But I always think SHE'S the one being mean, and I guess I just get into a bad attitude sometimes. It really *****, because when I do something mean ex. Call her or one of her other friends a name she yells at me that I don't ever say sorry. I want to say sorry so badly but when she tells at me a little voice in my head is like "you can't say sorry now, she's being just as mean to you". Yet I constantly rehearse apologies in my head to her. I just can't tell her how I feel. We are very close but I can't tell her i'm mentally ill. I once tried to tell her in a joking matter and she got very mad at me. She said that I should have told her earlier and that she couldn't trust me anymore, so I told her I was just kidding. I honestly don't know what to do anymore, this makes me so sad...

[drifter0213]

do you hear voices? have hallucinations or delusions? that is schizophrenia a form of permanent psychosis ok :)

[Toxic_Angel]

Yes, what I described in my question is not the only symptoms I have of schizophrenia, it's just the symptom I need the most help with right now

[drifter0213]

i have difficulty concentrating cuz of the voices i hear all the time like two women having a conversation and a third voice that makes insults to me the pills i take help me manage :)

[schizofriendia]

You might not have schizophrenia, have you spoken to a doctor about it?  If your friend is acting this way over you telling them you have mental illness, sounds like they have mental problems of their own.