My best friend is ignoring me

She started ignoring me for the past 2 days.When she feels moody and ignores me,it normally lasts for like half a day or so.Since it's been a bit longer thanusual,i think i've done something wrong but idk what.When i wave to her she flat out ignores me and looks away and screams our other friend's name,when i came out off class normally she waits for me but she ddint this time,when i waited for her she didn't even acknowledge my presence,when she saw me far away she ran to the opposite direction with our other friend,when I asked her a question she said "no" but in a really annoyed and deep tone but within a few minutes later she happily talks to another friend.It doesn't piss me off but rather makes me upset.Like if she doesnt want to hang out with me anymore than,okay!But atleast tell me first...

Like a week ago she told me about how her mum emotionally abuses her and i stayed there for her for when she needed someone to rant to.I even wrote an entire letter for her with a drawing and some prints for her.I don't understand what i did wrong.I thibk i do maybe have an idea of what mad he that way but its kinda minor.Her mum voiced messaged me on her number but my best friend told me to not listen to it,i was really curious so i lisnted to like the first 2 secs then deleted it.maybe thats why? but i honestly dont know what else i did wrong for this to happen.