What can I do to calm my nerves?

My closest friend in the whole world of 8 years blocked me this morning and said she doesn't wanna talk to me ever again, because of a misunderstanding.

This person meant the world to me.

My nerves are raging. I feel depressed, I have no appetite, I'm have a hard time holding down food 'cuz I feel like I'm gonna vomit. I probably won't be able to sleep to night. I don't feel like doing anything.

And I have literally no one in real life that I can talk to about it. I don't remember the last time my nerves were this high.

Any suggestions on how I can calm myself?

Updates
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I already had a bit of a breakdown
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I feel a little bit better today, but still not 100%. On the off chance the person in question sees this, I hope when you're ready, we can talk and patch things up <3
What can I do to calm my nerves?
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