That's what it is that you rehearse - the making of music, not the playing of notes as abstractions.
I'm lucky to have a great support system in my friends and some of my family. If you have those people that you trust, go ahead and fall back into them and let them be your hammock and cocoon and let them embrace you.
I'm not a doctor - so I can't describe flashbacks well - but it is like you're living it again.