I went through a traumatic experience last summer, and it significantly impacted my ability to write anything new. I couldn't even write about what happened--the fantasy short I started that referenced it was too painful to work on. I still break down when I try. I need more distance.
Yesterday, for the first time, I wrote 900 words that I really liked. Today it's up to 2k. Small potatoes compared to my normal output, but I'm grateful beyond articulation that I can do this again now. The last time I wrote something I liked was in early August. Everything since then has been dust and ashes.
So I went into an editing cave. That's a nice comfortable place to be. I studied story structure of different narrative forms. I worked my way through my TBR pile. I took notes on some of my favorite tales. I jotted down story ideas but didn't push myself to write them yet. I re-watched all my favorite movies and took notes on them, too. I researched agents and publishers and started querying a novel.
Basically, I filled my mind with the equivalent of comfort food. I tried to make it productive because you're right about wasting time only making things worse. Sometimes you just need some distance. I'd recommend finding something you can be productive with--even if it's cleaning a closet. Allow yourself time to heal.
Take notes on your feelings if you can face it. I'm fairly ruthless with myself, and I hate to waste perfectly good pain. If I'm going to hurt, I at least want to get something out of it. But you know your own psyche best.
Your ability to write isn't gone. Nothing can take that from you--it can only be surrendered. Your outline will still be there when you're ready for it.