Sleep regression

I don’t know what changed but my little one (sept 30) just won’t sleep. Screams when I put her down and only gets louder and more intense. Sometimes she falls asleep within 5 minutes of going into crib with some crying, other she just screams.

I try nursing to sleep but she wakes as soon as I put her in the crib..

anyone?

Is it sleep regression? Separation anxiety?